I am using IronFox (on GrapheneOS). But I don't really use my phone for browsing the internet very often.

Fennec on F-Droid

I use https://github.com/fork-maintainers/iceraven-browser for its ability to install any extension, including https://en.wikipedia.org/wiki/Bypass_Paywalls_Clean. If you don't need that, I'd recommend IronFox because of its explicit security goals.