I wouldn’t underestimate the ability for cultures to enforce themselves over time (though evolution is certainly inevitable).
The culture over on mastodon, despite huge migrations from twitter, has managed to have a persistent effect. Sometimes that’s been by pushing away people who don’t fit in (which has actually been controversial in some ways). But generally, it’s been by having a positive effect on people just like lemmy has on you (and me!) and encouraging such people to understand where that effect comes from and carry that effect forward.
Part of the idea of the fediverse, after all, is empowering us to take back the internet and make it what we want.