I subscribe to ones I’m interested in. But sometimes I browse all to stumble across new interesting communities. I block the ones I see repeatedly and aren’t interested in. I block mass posters, I block bots, I block tankies, I block mods/admins of larger communities. It just makes my all browsing time more efficient.
I just noticed a pattern of personality types that I didn’t mesh well with. So it’s best I don’t see their opinions, nor give them mine.
Like blocking all hexbear users. I’m sure I’m probably missing something worthwhile here and there, but overall my life is better without it.