If you think an ad-pocalypse is bad, then why would they jump to a platform with no ads at all? They’d likely be paying to be on that platform. Also the fact streaming video from a self hosting platform is much more demanding then text fedi instances like Lemmy or Mastodon. Also no way the fedi could keep up with even a fraction of YouTube’s creator tools, or their audience which is their bottom line.
YouTube will probably never be replaced. We can at least go for private front ends like Invidious.
I believe Matrix has the same encryption as Signal. Though there are some things that leak metadata, like reactions for some reason. Would like an investigation into it as well, as I pretty frequently use it. Obviously this is assuming it’s an encrypted chat. Though would also like to see the comparison of an invite only encrypted room, vs a public joinable encrypted room.