The problem for folks like me/us is fear of "losing" something, and like the OP. knowing that something can be saved and found again (or stumbled across) later solves the problem, whether it's ever searched for again. The act of "hoarding" actually scratches the itch for me. I'm fine to close a tab if it doesn't feel like I'm "throwing it away forever." And bookmarking a site is just a slower way to lose something forever. It's not easily findable, and I won't take the time to organize my bookmarks into a nice hierarchy. That reminds me of those old "internet yellow pages" that were sold at Microcenter back in the early days. That's a silly, slow way to organize information for retrieval.
I wish that 99% of my browser history was automatically indexed/recorded for later searching. I could imagine "boosting" particular links' importance with a bookmark concept, but I think you could also choose to elevate any site I spent a little bit longer on to actually read, or that I came back to later. If you added semantic search into that, and offline plain-text greppability, we'd really be in business. A lot of my searches boil down to "Didn't I see a tool or HN post that solved this problem 6 to 12 months ago?" Sometimes I find it again. Often I don't.
I keep hoping that someone like Kagi (which I already happily pay for) will let me build my own personalized internet index consisting "only" of the tens of thousands of URLs I've seen...They've built some stuff that is kinda close, and they already have a good crawler/indexer.
I have been using OneTab to quickly consolidate a lot of tabs to a single list of URLs, which actually does help me "feel" a bit better, but doesn't solve the semantic search issue. It sounds like Karakeep (mentioned by @miladyincontrol) does some of what I want already, and that they're working on semantic search too, but it doesn't offer it yet.
If anyone (including the OP) has something to help me auto-hoard, I'd love to hear it.