My experience as a young adult in the UK was that most people I knew had moved from Facebook to Instagram & Twitter in their early 20's.
Normal people whose interests would be things like football, going out drinking, and reality TV. The extent of their politics would be sharing a meme of Boris Johnson or complaining about COVID restrictions. I don't like the word 'normie', but that's exactly how you would describe them.
Looking through my following list now, these type of people have now either deleted their account, or haven't posted in years.
I don't think it's entirely political. But the rebrand to X and Musk's involvement made using it very uncool. It's seen of in the same vein as Facebook now, it's kind of embarrassing to admit you still use it.