i'm not sure what those cons are meant to be.
moderation can be implemented permissionlessly. nostr idea is it is simple and ppl can just implement stuff on top permissionlessly.
dat project https://cabal.chat implemented trust nets or subjective moderation, which allows people to freely choose their moderators or do it themselves. tools are follow, ubfollow, mute, block, etc... subscribe to specific content. configure your own algorithms.