The trouble is that people are inconsistent and multi-faceted.
I might really really value a particular friend's opinion on tech, but constantly roll my eyes and sigh when he live-tweets his hot takes on Eurovision or football.
It would be cool if Twitter could do some sort of clever analysis on a persons tweet history and when you start following someone say: "Dave often tweets about US Politics, Baseball, Skiing and Programming. Which of these topics do you want to follow".
Multi-faceted is the thing Twitter and other person-based share/follow don't work well with. I ended up creating another account for music/art, separating it from my tech/business activity. But its pretty tedious to manage...
I might really really value a particular friend's opinion on tech, but constantly roll my eyes and sigh when he live-tweets his hot takes on Eurovision or football.