discovery is a vector for harassment
this is a valid concern but of course you enunciate the other valid concern: sharing is the whole point of social media
we don't have to say "grow a thick skin and use to learn the block button" (which doesn't even work for committed harassers and brigading) we just have to make discoverability opt in, and I think mastodon is doing that now with search indexing
PeerTube just has to do that too (unless I misunderstood the exact technical impediment here)