I switched from twitter to threads pretty much immediately and traffic there comes and goes in waves when people get freshly annoyed at twitter about something. Most of the people I followed on twitter have threads accounts -- most of them crosspost there frequently, some of them only do when they're mad about something elon musk did and then go back to twitter.
The most obvious answer is people who can't stand Tucker Carlson or Alex Jones types. Lots of high profile political accounts have moved over from X. In the politics vein, lots of Ukrainian and Ukraine watchers as well, oddly enough. Aside from that, some machine learning accounts are pretty decent and have a growing community. - my 2ยข
An algorithmic feed of posts and replies within a post means that you see whatever an optimization function thinks will maximize revenue and engagement. And people on both sides fall for the bait and engage when they're shown what they disagree with.
You would think so, but it sure feels like all of the ad slots in my feed are almost always inundated with promoted posts from random rage-baiters on the right. I even muted "Trump" and a bunch of other politics-talk and still see it daily through ads.
Add to the fact that X is also trialing ads that don't get labeled as ads [1] (and just get promoted to your stream as if they're a normal post, but still have the "Why am I seeing this ad?" etc context menu), and it seems like there's more and more avenues every day for content to creep into your feed whether you interact with it or not.
Yes, you can absolutely curate your feed by following what you want to see more of, marking suggested tweets you don't like as see less often, block people etc. This is a non-issue.