Have you ever seen a 410 actually used IRL? This has to be one of those that's pretty high up in the code rarity list.
From a user perspective, getting a 404 after following a link that previously worked can indicate a couple of things. Like maybe the resource still exists in some other place, but they didn't set up redirects. Maybe it's been "privated" in some way, and I no longer have access to it.
A 410 makes it explicitly clear to me, that the resource has been permanently deleted. It'd also be nice if the response included some metadata as to when the resource was deleted.