If Medium does go away, I suppose I'd take the backups and just go through and repost everything on another platform, or simply set up my self-hosted blog again.
Yes, that would be immensely annoying, but it's not really that terrible of a downside in a calculated risk offset against how much easier (and, again, free-er!) medium is to use, and to maintain.
I think Medium is nice too and will be doing some writing there.
I think I'm looking at things over the span of 2 decades of keeping one's presence and information online whether self-hosted or with a service, both of which come and go.
Yes, that would be immensely annoying, but it's not really that terrible of a downside in a calculated risk offset against how much easier (and, again, free-er!) medium is to use, and to maintain.