My SO struggles with this too. I just get by with only one or two people I’d call friends and that works for me. I don’t need a lot.

But my SO struggles with friends in much the same way. They are always the one to reach out to the friends and ask to schedule things and plan in advance but it’s never the friends reaching out to do the same. I consider those not real friends - they’re friends out of convenience because it gives them something to do sometimes instead of actually caring.

So maybe keep track of things like this and see if your friends are actually friends and they care about you or because they get bored and occasionally want things to do.

It seems to me to be pretty normal as you age to distance yourself from others. Especially if you’re in a relationship and/or have a career or job you’re passionate about which it appears you care a lot for your field. Those two things alone will eat up the majority of your time. Throw in friends with that who also may have relationships and jobs etc that eat up all their time too. So naturally it’s difficult to plan things and people fall apart. Totally normal.

Friends grow apart, it happens. Making friends gets more and more difficult.

You can decide how much effort you want to maintain relationships, and how much you invest in new ones.

It looks like you started a journey of self improvement this process can last a lifetime. At some point I discovered that people are really interesting and diverse, especially as they grow older

I think there is a celebrity book "How to talk to anyone" that would be helpful. TL;DR - interview people

Everyone’s life and experience are different.

In general I would say this is a common experience around this age, at least in western cultures.

However I think there is no rule to life, friends depend on a lot of things, from both sides, so they can change throughout your life. It is up to you to try and foster the ones you want.

A few things:

1. It is common for people to change in their late 20's. Goals change, people change. It is fine that you are closer with a different group of people.

2. You can be friends with people in different industries; you just need to find some sort of common ground. If you can't find any common ground, then it is common for friendships to drift apart.

3. A lot of people don't like being corrected. I get that you want things to be right, but it can be an insufferable personality trait in friendships while it is necessary in your profession. You have to learn when it is ok to let incorrect things go if it won't hurt anyone.

There are always things people have in common. More-so today with the accessibility to media provided by the internet. That said being a friend to someone isn't about checking a bingo card of similar interests. It's about listening to their experiences and being interested.

What do people watch on tv, what are they listening to, where have they vacationed recently, did you hear about xyz happening in the news.
Kids. People with kids talk about their kids.

Some of that might overlap with your experiences, some of it won't, it doesn't need to. You just need to shoot the shit, hear what they've been up to, say what you've been up to, and enjoy doing it. Maybe do an activity of somekind while your at it, maybe just eat dinner.

The age range is just when people get busy with life and have less free time to actually do things. So they have less to talk about. Work becomes their lives. That changes eventually, wait another five year period. You get settled in your career and your focus shifts more towards what's going on in your actual life.

You should look up 'speech communities'. It's a linguistic anthropology thing. Essentially boils down to 'people talk differently and about different things depending who they're talking to and where'. In your case you want a group of work friends to talk about work topics with, separate from your group of childhood friends, who you can talk about non-work topics with.

If your lucky, your childhood friends will follow a similar career path as yourself. Observing siblings and acquaintances, the ones that seem to have maintained friendships from school to older ages are only the ones that ended up having similar careers in particular sectors that allowed them to remain near their childhood homes.

Personally I took a fully different path and moved thousands of miles away for work. After a few years there simply was little in common to discuss with friends even after I moved much closer. I certainly envy my old friends that stayed together. While the decisions I made have been very successful and rewarding, it came at a cost. Making new real friends when older is pretty difficult and you have to put a great deal of effort into it.

I was 13 when COVID started, and after, I felt the same thing. I felt more mature, got into tech, lost some friends and gained new ones.

I'd say my teenage years were my butterfly years, but really it's different for everyone. Maybe COVID was the common factor that did it, at least for me and perhaps for you too?