For private use: I rarely bookmark anything anymore. Lots of info is easy to find (e.g. Arch Linux Wiki) and reasonable reliable. Also my password manager has a list of all accounts with associated URLs, so I can search that.
For work I have a wider variety of information. I'm often doing Pentests, so I read up on related research a lot. Since I can't keep every minor detail in my head, I bookmark interesting things in the browser; that's then backed up, but that's about it.
As a typical tech hobby, I run a few home servers and recently got myself an "always on" machine. Now I'm looking at self hosted services my family and/or I could genuinely benefit from. Bookmark sync between my work laptops could be nice, but Yacy mentioned in the top comment is insanely attractive - indexing (+archiving?) beats bookmarking.