I used to watch live/vods of every team, now I really only watch sen games or occasionally what sliggy is watching. I don't think I could tell you who is on half of the teams
Honestly it depends on the quality of the teams and the importance of the matches. The only teams i faithfully follow are the BR teams or teams that have BR players like Vitality on EMEA.
I just put Sliggy's stream in the background and play something alongside it if I don't really feel the hype from the game.
If the game is good then I just lock in