X is undoubtedly still the largest, but I think it has become a very toxic and negative place. The replies section on this post, for example, is full of hostility, racism, crude jokes, and memes. I don't know who finds joy in that sort of thing, but it isn't me. I'd rather read positive things and get along with people.
I really wish everyone (and it really did seem like everyone) had followed through with their threat to quit "X."
Aside from the toxicity etc, the website itself is purposely extremely difficult to read. One of the worst examples of the design trend today of making it very difficult for the user to see what the user wants, because the purpose of the service is to constantly push what the service wants the user to see. Textbook example of enshirtficiation.