I think there's a lot more to this phenomenon than a quick quip. The fact that a good post can have an extended shelf life in a context that rarely produces flashy virality is a function of both the technological infrastructure and the much more human and real social norms here.
This is one of those things that I meant a couple days ago when I said to newcomers that a lot of the good parts of Mastodon/fediverse take some time to notice and appreciate.