My engagement with Twitter has lessened significantly since Elon bought it, but probably not for the same reasons most other people cite. I have long found the official Twitter app to be hot garbage, and had been using the far superior third-party iOS apps Twitterrific and Tweetbot for over ten years. A few months ago, Elon cut off third-party developer access to Twitter's API without any warning, meaning all the third-party apps suddenly stopped working. I tried using the official app for a while before giving up, and now when I do look at Twitter, it's either via the website on a computer or not at all. I never used the algorithmic feed, and have always preferred the chronological feed, which in concert with the now-defunct apps allowed a much better degree of control over what you wanted (or didn't want) to see in your feed.
Reddit has also limited API access recently, announcing they would start to charge huge access fees that most developers won't be able to pay, so the most popular third-party app, Apollo, went dark a week or two ago. They are preparing for an IPO, so I expect other changes to follow which will be in the best interests of the investors and not the users.
Facebook I have long regarded as a necessary evil, as it's the only social network that many longtime friends and acquaintances use. I've never had an Instagram account and don't intend to start now, so I won't be on Threads.
Mastodon seems to be the most promising, but as others have pointed out it has a long way to go to reach any sort of critical mass. Decentralized networks like Mastodon, and Usenet long before it, are a far better option than the walled gardens that practically every VC-funded/publicly-traded social network has implemented. The walled gardens' only interest is in mining user data and monetizing it, and that means engineering their sites and apps to keep users' eyeballs on them for as many waking hours as they can. Why this is a bad thing should be fairly obvious.