Some think that by changing a service they can get better replies, but there will be no single service that has "sane commenters". This shouldn't be surprising, I saw in Threads complaints that replies had "Facebook vibe", or a common complaint about Mastodon that there were too many geeky reply-guys.
Services should have good filtering in place. A lot of big accounts don't have time to read replies, and they probably shouldn't for their own sanity, but they probably want to see replies from people they follow, i.e. their peers.