I use firefox mostly because it's not blink based, and because I've used it all my life, but I also really love the userChrome system even if its hidden behind a flag. Since I use mostly vanilla gnome I use a firefox libadwaita skin [0] that makes it blend in nicely. I used to be jealous of chrome based browsers for their performance but I tried to switch to brave a couple years ago and honestly it doesn't look or feel very nice.
Most chromium-based browsers feel the same and its disappointing. If I wasn't as happy with the gnome skin for firefox I'd probably be using Zen [1] because its nice to see a firefox based browser that tries to introduce new features and create an identity of its own instead of joining a size measuring contest on how hard(ened) they are (I respect them, but it's a very saturated market at this point).
Editing to add that like @WarOnPrivacy said, containers are also a huge feature that I don't think I've seen any chromium-based browsers replicate.
Most chromium-based browsers feel the same and its disappointing. If I wasn't as happy with the gnome skin for firefox I'd probably be using Zen [1] because its nice to see a firefox based browser that tries to introduce new features and create an identity of its own instead of joining a size measuring contest on how hard(ened) they are (I respect them, but it's a very saturated market at this point).
Editing to add that like @WarOnPrivacy said, containers are also a huge feature that I don't think I've seen any chromium-based browsers replicate.
[1]: https://github.com/rafaelmardojai/firefox-gnome-theme [2]: https://zen-browser.app/