Honestly, since the first day I switched to Firefox I'm just saving to it's own bookmarks. Whenever I wanna check those websites I just open it either from my desktop or my laptop(s), since it's syncing in between my devices.

I don't know if there's much people using bookmarking tools, but to help you see another perspective, as a person who finds bookmarking tools not necessary I'd say it wouldn't worth your time to vibe code one. Also just for "vibe coding", be really really careful if you're gonna make it a "product" because you'll definitely face rough situations through it.