Here's the critisisms section excerpt from Wikipedia that I mentioned in my other comment, incase you just don't feel like clicking offsite. This is more or less a synopsis of the most serious issues. The fan culture section of the article is is also worth reading if you're curious to learn more about how intense the parasocial element is

From: https://en.wikipedia.org/wiki/Japanese_idol?wprov=sfla1

Working conditions

The idol system has been criticized for its strict rules, intense work schedules, and offering idols little control over their personal lives. The system has been likened to salarymen in Japan who are unable to disobey their employers. Labor rights activist Shohei Sakagura stated that idols get very little revenue and are ill-prepared for the work force after leaving their groups, as many of them spend their academic years learning poor job skills. In addition to this, Rob Schwartz from Billboard addressed that Japanese mainstream media outlets rarely bring attention to controversies and allegations of power harassment due to self-censorship on what they are allowed to write. Sasetsu Takeda of GQ Japan wrote that talent agencies dismiss idols regardless of their popularity, sometimes intentionally blocking job offers in order to pressure them to leave, all while declaring that they are "resting from illness" to the public. Independently managed idol groups offer even less protection, with idols given ambiguously worded contracts that keep them in their companies for years, while offering almost no pay and compensation for transportation and costuming fees. Lawyer Kunitaka Kasai stated management may be poor, especially among independent idol groups, because they were established by people with a lack of experience to fill a demand for idols over the industry's growth.

Work schedules for idols have been criticized for being excessive, as idols are expected to work even when sick. Miki Gonobe from Nikkan Sports noted that idols generally do not have a labor union and agencies see no need for one, as they view idol activities akin to extracurricular activities at school. She voiced concerns about young girls becoming idols at an early age, especially elementary school students. In addition, Sasetsu Takeda of GQ Japan criticized some idol managements for intentionally preventing their talents from taking time off, mentioning it "strange" that idols are only notified of their assignments the night before. He also condemned the idol industry for not providing talents access to better mental health resources, as idols are often suspended or dismissed for publicly showing they are stressed out of concern that they may cause fans to feel worried or upset.

In March 2018, Ehime Girls member Honoka Omoto died by suicide, with her family launching a lawsuit against her talent agency in October 2018. Allegedly, Omoto was working 10 hours a day at the expense of her studies and when she had asked to leave the group, a staff member threatened her with violence while Takahiro Sasaki, the head of her managing company, told her she would have to pay a penalty fee of ¥1 million. In June 2018, a former member of Niji no Conquistador filed a lawsuit against Pixiv representative director, Hiroaki Nagata, and the group's management companies for voyeurism and sexual harassment during her time with the group, and Nagata filed a counter lawsuit for libel and resigned several days later. On February 10, 2020, the Tokyo District Court dismissed his claims and ordered him to pay ¥1.1 million to the woman in damages.

Dating ban

Minami Minegishi (pictured 2009) made international news in 2013 after a video of her with a shaved head as penance went viral. This followed news reports suggesting she was in a relationship, which led to her demotion in AKB48. Most idols are not allowed to form romantic relationships or must obtain permission from their agencies to get married. Yasushi Akimoto, the producer of AKB48, likened the group's dating ban to similar dating bans for baseball teams competing at the Kōshien, where dating is seen as a distraction from preparing for tournaments. On the other hand, critics have suggested a dating ban is implemented in order to sell a fantasy of idols being accessible to their fans and disagreed with them for being inhumane. The Japan Times noted that aside from talent agencies, idol fan culture has contributed to this, especially with male fans of female idols; male fans buy into the idea of "moe", which fetishizes weakness and submissiveness while asserting "complete control" over the girls' sexual independence.

Several idols who were confirmed to have been dismissed, suspended, demoted, or forced to leave their groups following reports of them dating or having sexual relations include Mari Yaguchi, Ai Kago, Aya Hirano, Rino Sashihara, and Minami Minegishi. Minegishi, in particular, caught international media attention after her apology video went viral, causing international criticism over the management of her group, AKB48, as well as the Japanese idol industry. A talent agency filed a lawsuit against a 17-year-old former idol singer for accepting an invitation to a hotel room from two male fans, which had caused her group to disband within the first 3 months of their debut. In September 2015, Judge Akitomo Kojima, along with the Tokyo District Court, ruled in favor of the talent agency and fined the woman to pay ¥650,000, stating that the dating ban was necessary for idols to "win the support of male fans." In January 2016, a similar lawsuit filed with the Tokyo District Court ruled in favor of a 23-year-old former idol, with Judge Kazuya Hara stating that the dating ban "significantly restricts the freedom to pursue happiness."

Since handshake and other related events allow fans to be in close proximity with idols, critics also believe that marketing the idols' accessibility may cause fans to be unable to distinguish between fantasy and real life. Talent agencies have also been criticized over offering inadequate protection towards idols after several incidents of violent attacks on female idols such as the saw attack on Anna Iriyama and Rina Kawaei, the stabbing of Mayu Tomita, and the assault of Maho Yamaguchi.

Sexualization See also: Junior idol § Legal status, and Child pornography laws in Japan

Idols are often sexualized, especially female idols, some of whom also work as gravure idols and have suggestive swimsuit photo shoots that are published in magazines targeted towards adults. With the idol system commodifying youth, the industry is criticized for putting minors at risk, most particularly junior idols, who are aged 15 years and younger. Idol swimsuit photo books are often sold in the same sections as pornographic titles. In 1999, Japan banned production and distribution of sexually explicit depictions of minors, which outlawed photo books depicting nude junior idols. Multiple junior idol distributors closed after possession of child pornography was made illegal in Japan in 2014. However, junior idol content currently stands on legally ambiguous ground due to open interpretations of child pornography laws in Japan.

In 2017, through a survey conducted by the Japanese government, 53 out of 197 women contracted with talent agencies stated that they had been asked to take part in pornographic photo or video shoots of which were not previously disclosed nor included in their contracts. 17 of the women stated that they had performed the request anyway.

I don't think you're wrong at all to think it's wholesome! I just also think your initial comment relfects a lack of context about what idol culture is like, it's a lot more toxic than being a child actor or singer, or being on Nickelodeon. Where abuses sometimes, or perhaps even often happen there, and the exposure to celebrity from a young age can be really bad for kids, idol culture and agencies codify and intentionally facilitate things that are bad for kids.

And to be very clear, I don't see it as a personal failing for someone to not know about this. It's a distinct thing from other cultures that most people here have no exposure to, and it doesn't disallow you from appreciating this nice occurrence.

In 2014 when child pornography was outlawed, there were a number of idol distrubtors who closed due to the ban because it used to be very common to produce child pornography of idols. It is still a thing that idols are asked to participate in (idols age out at 25, I haven't investigated the age range of idols in the survey):

In 2017, through a survey conducted by the Japanese government, 53 out of 197 women contracted with talent agencies stated that they had been asked to take part in pornographic photo or video shoots of which were not previously disclosed nor included in their contracts. 17 of the women stated that they had performed the request anyway.

That was taken from the Wikipedia page (https://en.wikipedia.org/wiki/Japanese_idol?wprov=sfla1). If you read the section on critisisms I think you'll start to understand what I mean, as it's pretty horrific, especially as a thing to subject children to. The agencies and culture around idols are HIGHLY exploitative, intentionally by design. They're exploitative in terms of labor practices, in terms of sexual exploitation, and they (by definition) subject children and young girls to levels of parasocial obsession that pretty much doesn't exist outside of idol culture to the best of my knowledge. That parasocial obsession is what the girls' public image is designed for and marketed on, and it has escalated, not just to stalking or harassment, but violence on multiple occasions, which the Wikipedia page covers.