I'm a user that uses bookmarks a lot. I like the way bookmarks get synced across devices. They are easy to manage. But, there is one crucial thing that's missing for me, and that makes me still use a 3rd party software (Raindrop.io), it's thumbnails.
To provide an example, I bookmark a lot of music from various platforms (Youtube, Bandcamp, Soundcloud, etc.). I do this simply because bookmarks are the only convenient way how to centralize it. However, my brain can't really recognize most of these links after a few days just based on the title, but it's much easier for me when I get the visual clue of seeing the album cover or image associated with that music link. Without it, it all becomes just a bunch of links that I'd have to click through again to re-discover the content or find something specific.