There are a bunch of great accounts to follow that are only really posting content to x.
Karpathy, nearcyan, kalomaze, all of the OpenAI researchers including the link this discussion is on, many anthropic researchers. It's such a meme that you see people discuss reading Twitter thread + paper because the thread gives useful additional context.
Hn still has great comment sections on maker style posts, on network stuff, but I no longer enjoy the discussions wrt AI here. It's too hyperbolic.