On desktop, FF supports the best vertical nested tab tree I have seen. What I’ve seen on chrome is laughably amateurish with huge chunks of wasted space due to unmodifiable(?) padding elements
1200 thumbs up since 2022 and 22 pages of comments. I wonder when we'll get native vertical tabs.
To get it that way takes a bit of code in the advanced options, and tinkering with a user definition file in FF to remove the top tab bar, but it's worth it.
The other killer feature of FF for me is the ability to containerize domains and control how cross-domain containerization occurs (https://addons.mozilla.org/en-US/firefox/addon/containers-wi...). My interactions with google (for example) never leak out of my google container, so my search queries or browsing aren't explicitly linked to my google account, because I do that outside my google container. Want to watch a video on yt without it tanking your recommendations? Do it outside the google container.
Of course there are a lot of other ways for google to infer it's "me", so I don't know if this is pure security theater or it actually hinders them building my profile. Either way, it's nice to be able to explicitly determine when and where my google profile is built as I traverse the web.
I also set the preference browser.compactmode.show=true to enable the "compact density" in the customize toolbar section. Good use of screen real estate with these changes.
I will not defend this use model to any skeptics, but FWIW I have no performance issues!
Sidebery lets you set colors on tabs explicitly, or by pattern. I use this sparingly but it's very useful when I do.