I went to Mastodon first, about the same time Twitter officially went into Musk's ownership. I've only looked at Twitter to find fellow refugees from the friends I was following there, but quickly gave up - some people moved over and I was able to follow them, but most went elsewhere from Twitter (mostly Cohost or Itaku) or just remained on Twitter because "that's where the audience is". But I've been happy on the fediverse - I've found that my corner of it has been a lot less about 'drama' and more about sharing personal experiences or news. It's nice!
This whole Reddit thing has been my first look at the 'threadiverse' as some have called it. I'm looking at kbin specifically if I end up setting up an instance for my community, but I'm all in on this decentralised social media now, and I really want it to win out.
The background notifications will be nice! I'm using ntfy for (among other things) notifications for a housemate that isn't as tech-savvy, so it'll be nice to get them smart home notifications that they don't have to keep a tab open for (if I understand this correctly).