Social media feeds are designed to be slot machines. Each scroll is a pull. You may or may not get something you actually want. You can't predict what's coming up next, so you just keep mindlessly scrolling.

It's not just the scrolling, the posting side too. They all randomly boost one of your posts so suddenly tons of feedback (especially noticable when I tried threads) and then you try to get that back again. The uncertainty keeps you at it