I use Pinboard.in and I've done so since 2008 (that's my earliest bookmark). I remember landing on Pinboard because something was going on with Delicious. Enshitification, I'm sure.
I use it to save bookmarks with hashtags, then search for those hashtags later when I want to find it.
It's just really interesting how different the mindsets are today, compared to back then. I remember "cloud first" being a thing people were pushing and talking about. Today everyone is talking about self hosting.
All that to say, Firefox allows me to save bookmarks with hashtags. I think I might cancel my subscription to Pinboard. The guy running it is a good person and he's doing it on his own so I like supporting that buttttt do I really need to put my bookmarks on other people's servers?