I'll give raindrop.io a try next week to see if it meets my needs, but I think in the end I'll have to roll my own since there are some features I want that I simply haven't found in any bookmark app or extension.

Some of these are

-pin bookmarks or folders and sort the rest of bookmarks in that folder

-search bookmarks by name or tag in a group of folders

-have something like sessions where only a custom groups of folders are visible