We just don’t smell the rot yet. It’s not about the actual body (website) and the name. It is about the spirit, the personality. And that has been compromised and killed off because of factors one could call enshittification or whatever. Digg and Tumblr still exist, at least in name, but not in spirit. I think Reddit has past that threshold. It will be a slow death and I am not sure the fediverse will fill the void it leaves behind. But I do think and believe communities will never sustain on venture capital.
‘the best’ is subjective. Yes, tumblr still exists and perhaps has a second life. But the spirit of the old tumblr is gone. Same applies to Reddit. It’s not the name or the site that died but its personality. Twitter is a good example. It died a few years ago, slowly. It is still around but what made twitter twitter is no more. It changed, it has another atmosphere and other types of users. It is still called twitter but that is like a son who has the same name as his father. Two different persons.