Depends:
single platform: there i talk mostly about features like no tracking and no ads but also add that there are less people but its still lively

Fediverse: "imagine you comment under a youtube video with your twitter account", then i add that i actuallynever did the equivalent but that its possible, then i rant about bsky not being decentralised (because DIDs) and its red flags, then go back explaining fedi and reference it to email