I'll give you a hint: actually try it

That's fine too, but making broad statements without anything to back it up isn't really a good look.

I didn't mean to suggest to go all in. I meant literally try using RSS/Atom for that. You'll run up against a bunch of walls real quick.

Sure, RSS/Atom can do a reasonable job of recreating something like the Twitter home timeline. But oh, you wanted to reply to something? Favorite a tweet? There’s nothing in RSS for that.

Don’t forget posting things other than blog posts and text. You want to post a photo? Sure you could embed that in a blog post I guess. A video? now it’s getting tricky. Maybe use Atom enclosures? Posting multiple photos to be shown as a carousel like instagram?

Don’t forget that RSS is by definition unable to evolve to include other richer post types than just blog posts. Atom you could start to shoehorn other things into by adding namespaces and such. But does anyone really want to keep writing XML?