Others have commented that Chrome does this already.
Edge also does all or almost all these things. Bookmarks bar might be disabled by default, but iirc it is a right-click away, and only has to be configured once.
Safari also supports everything here. The “Tab Groups” feature in combination with the bookmarks bar (which safari also supports) makes it super easy to maintain persistent tab sets or just keep certain things separate (the research rabbit hole use case). Tab groups persist between sessions and sync across devices.
I think safari tab groups are intuitive, efficient (no performance impact that I can see), and super prominent.
After a year of using an open source and self hosted ecosystem, I recently went all in on the Apple ecosystem. My main concern was avoiding trusting Google and other companies with advertising-based business models. I think Safari is really the best browser out there these days in terms of avoiding ad tracking, plus it has the most efficient energy usage of any browser on my M2 Mac. I've been pleasantly surprised by the tab groups feature, especially how seamlessly it syncs across devices and persists across sessions. It's everything I've ever wanted from browser bookmarks. I also like that when I try to open a website that's already open in another tab, it switches me to that tab automatically. I'd be more comfortable if I could easily export the tab groups to a text, yaml, json or xml format that I could convert to bookmarks in another browser, but other than that, it's perfect.
I'm not a heavyweight user of bookmarks. But I do love vertical tabs and grouping, which can be collapsed. Moreover, they can be saved to collections (to get rid from tabs) and collection can are restored as groups. Notes can be added to collections or entries, tho I don't use it
Anyway, not that there would be some kind of search for collections - not even the URL bar detects items in there.
Edge also does all or almost all these things. Bookmarks bar might be disabled by default, but iirc it is a right-click away, and only has to be configured once.
Safari also supports everything here. The “Tab Groups” feature in combination with the bookmarks bar (which safari also supports) makes it super easy to maintain persistent tab sets or just keep certain things separate (the research rabbit hole use case). Tab groups persist between sessions and sync across devices.
I think safari tab groups are intuitive, efficient (no performance impact that I can see), and super prominent.