Re Community Notes: On X it requires more than voting. X has a ideological profile on users. Notes need a high rating across the political spectrum to show up.
For the fedi: it could be interesting if there were self-appointed fact checking accounts that readers could *opt in* to (I'd personally opt-in to fact checkers across the spectrum). And maybe readers flag posts as "please fact check this". I wonder if it could even be an overlay system without Mastodon's help or even approval.