@nprofile1q... This isn't new and it isn't limited to online spaces. People have been choosing whether or not to associate with each other for millennia.
I will say I rarely block or unfollow people.
I generally reserve blocking only for those who do ugly malicious things like trolling, deception, or hate.
I have occasionally unfollowed people because, although they're good people, they've made a habit of posting things my stress-ravaged mind can't handle. But only occasionally.