I can sympathize with bookmarks problems, not only they rot, but after few years there is a lot of 404 (pinboard provides archiving bookmarks but that is a paid service).
Do you have a lot of Anki decks of just a single "random things from the bookmarks"? Do you use Anki every day or rather infrequently?
The main problems with all these systems are just that we use them to attempt to augment our own intelligence/utility based off of some concept of who we are aiming to be in the future, and then as things change for us personally, our aborted plans lead to a lot of rot that doesn't clear itself away automatically. So only some small percentage of what we collect ends up relevant.
I have a lot of individual Anki decks, which isn't recommended. But I create a filter deck that rebuilds from the other decks every day and properly randomizes the cards, and only study from that. I do it every day except when I forget and then I catch up later. My cards are mostly along the lines of music, logic, math, stats, programming, and rational thinking.