Plenty of life in some of those on the list when it comes to old farts keeping old systems running - Atari scene is quite active. Not to mention many of the other system "scenes" are a HELL of a lot more pleasant to deal with, lol. The Amiga scene has always been a volatile trainwreck.
"Outlive" is a pretty twitchy word to use for any hardware that's a good 15-20 years dead and buried. In the grand scheme of things, I suppose the Amiga is "still alive" in forms like the SAM, MorphOS, and even AROS. But the true "original" Amiga, well we've been poking that corpse with a sharp stick since 1994 when C= went belly up, and we'll never agree on which one of the machines that came since then was the true successor.
At this point we should all just be thankful there's a following for these old machines and that there's a community left to support them. Places like A.org are a huge asset to guys like us that dig this old gear, even if said forums often seem as a group of zoo monkeys flinging feces at each other