Why wouldn't you let people decide themselves though? Why does someone need to intervene, maybe some like the spam from one account, etc.

They could decide for themselves, it just takes a few more steps if they really wanted to try. But I think twitter is more like a few minute peek or a doom scroll session that tries to hook you into spending more time in the app and the algo tries to push posts with more engagement thinking it's interesting so that you'd stick longer to check out what that interesting is then multiple by few more similar posts based on your behavior just enough to make it a worthwhile scrolling session.

I follow artists and cosers there, and I don't have the time to see each of the daily posts OR have the memory to remember all names. And I may not have the time to discover other content creators showcasing my similar preferences so the algo does me a favor by shoving me content I might like and more than half the time, it works. The algo's way may not be your type but it's working for those belonging to the middle of the bell curve, for now.