Organize them into folders. All of them, with no exceptions. Having to take an action on each one will lead to removing many. Hoarding is a symptom of procrastination.
This. In my experience I've found plain bookmarks arranged in a sensible hierarchy of folders to be the most portable and incurring the least unnecessary cognitive load on me. Unfortunately once you allowed them to build up uncategorised, the effort to shelve them away properly will appear arduous. But better late than never.