Lol no, ReVanced also depends on app side changes, they could harden the YouTube app and make it more difficult to modify. The only upside is that it would take several months for those changes to actually start affecting users, when the old versions of YouTube are phased out.

OR, they could just block ReVanced on the server side and ban everyone that uses it, if they wanted to

Don’t be naive and think that Google can’t easily block ReVanced. They just haven’t tried to yet. They’re one of the biggest companies in the world, if they gave a shit it would be gone overnight, just like Vanced was.