The only positive change I can remember in the last 5 or so years (besides maybe extending the character count which I'm neutral about) is the toggle to go back to chronological tweets. You used to have to use lists of Tweetdeck, then they added an option but was hidden away or didn't stay default.

For all the hype AI/recommendations algorithms get I don't think it works well on a platform where you already choose who to follow.

Otherwise I've always wondered what the thousand Twitter employees do besides keeping the site running and advertising sales/development. Although I've never worked at a giant tech company before.