>It feels like a kind of end of civilization or even humanity type of thing, where at some point all of the earth will have been excavated and all human evidence will have been removed and catalogued and archived in some warehouse, totally sanitizing sterilizing the planet of human activity.

My understanding is that most countries prevent areas from being wholesale dug up, but only permit smaller, limited digs for this reason. So a representative sample of a site can be reexamined at a future date with future technology to reassess understanding. Some sites have had many many digs in this fashion, and still havent dug the entire site. In fact its a criticism of some semi famous sites, usually from charlatans, that the entire site hasnt been dug therefore we are leaving evidence of their popular wackjob ideas in the ground

>because there is very little of anything physical that remains.

I dont know thats true. Lots of what we do is kept and recorded. And our activity surely leaves traces. Plastics especially.

>My understanding is that outside of specific medium, none of the data we generate or consume will last, let alone survive something like a nuclear war or even a massive solar flair.

I dont believe this is true either. We arent backing our society up to a single old spinning disk. We have documents that immediately predate data storage. We have old documents stored in multiple places. We have lost certain specific artefacts of our own history but it seems doomerish to assume thats what happens universally.