I've been using fediverse daily since December 2018. I have my share of accounts that I have muted. Just now I downloaded that list of muted accounts and wrote a little script to see which ones were still online. Very few of them, relative to how many were on the list.
The answer for me as an individual is that if I'd just ignored them, not even bothered to mute them, they would have stopped appearing in my feed anyway.
It wasn't wrong to mute them, nor was it the only means to not see them.