Anecdotally, my own search engine index starts to feel stale after about two months. I wonder what the half-life of a link is.

I'm highly tempted to run a "caching" proxy 24x7 just to keep archives of some of these decaying gems around past their lifespan on the web.

I'd say I could just use archive.org (or similar), but their (admittedly necessary) respect of robots.txt makes their archive incomplete.

I've considered running my own IA (https://github.com/internetarchive/heritrix3), which only archives my chrome history, which is stored in a local sqlite db.

I haven't had the time to figure out the details of how the pieces should be glued together.

I also wish for a modern local archiving solution. HTTRACK just doesn't cut it anymore, unless you really want a local copy of a webcomic that stopped updating in 2003.

I use screenshots on my search engine to work around this issue. If you are interested, I have an open server deployment for it.

It won't help with ones that are already gone, but there's a firefox plugin called Archiveror that automatically archives your bookmarks.