Google Bookmarks. And I'm a long-term, heavy user.  Trying Saved.IO free version as an alternative.

https://screenrant.com/google-bookmarks-shutting-down-when-alternatives/

You're right - I've never heard of it

I use it a lot. If I think the source page will disappear (ex: classified ad, blog post) I put the salient info in the notes section. GREAT for research.

Saved.IO has the same basic features --notes and categorization being must-haves.  But the provided bookmarklet didn't have categorization on-the-fly.  I found an alternate one that does;

https://codepen.io/wuz/full/nwjqK

I've been using Pininterest.in. Its not free but its reasonable.