> They allow me to keep a long history of things I've found that are interesting, or useful, or otherwise important.

Bookmarks alone don't quite do it because stuff is moved or dies. A saved copy of the webpage does do it, though, along with the bookmark. SingleFile is a godsend here. I also really like Shiori and other similar bookmark managers that snapshot the webpage along with the bookmark. Even if the saved copy is incomplete or not high-fidelity, it's often enough.

For me, it's moved or dead infrequently enough that it's not a problem.

And given how dynamic and interconnected content on websites can be, I don't see a lot of use for snapshots - too much would be missing from a snapshot. Could be nice for an in-case-of-emergencies though, at least you've got something.