People jump on the bandwagon of "social media and smartphones are the problem". Most people are sockpuppets, and just repeat this without thought.
If you mean indirectly, then maybe.
I think the problem is late stage capitalism, the increase in exploitation and cheating just to get money, and the real and encroaching fear of fascism or fascism-lite.
Inflation is increasing. Cost of living, housing, food and essentials are rising. Overtime culture is on the rise. Why would I be happy when the outlook for most of us is shit? I have to work long hours just to survive and there's no escape. Buy a house, go into debt for 30 years with the knowledge that the bank is getting massive amounts of free money in the form of interest, and they provide no service other than allowing you to pay an overpriced principal over thirty fucking years.
Work until I'm 67? What's the point? It's time to die at that point as ill be too old and who gives a shit anyway. I'm supposed to be appreciative of my 3 weeks PTO per year, that's when I can go have fun and enjoy life, after that back to working unpaid overtime for a billionaire investor or CEO or whatever.
Maybe social media and smartphones are helping the young see how shit and hopeless our society is. Unless you can figure out how to be a celebrity, or an investor, or a landlord/landowner, you're stuck working a shit job until you're old and life is gone. Why the shit fuck would people be happy and want to have kids?