That's nice, I generally like setups like this that capture content and give me control over things (I've seen something similar on HN with passively saving any papers in PDF format viewed in the browser and then building fulltext search on top if, or e.g. approaches like this: https://github.com/thesephist/monocle).

That being said, in the spirit of my comment — I honestly don't care too much about what I might be missing due to sites going down etc. anymore. The truly great stuff I save somewhere offline, but that's one or two levels past all the random things I currently use bookmarks for.