As a Firefox user since its beta, there is? Last I checked there remain 3 browser engines left. Mozilla’s Gecko, Google’s Blink, and Apple’s Webkit. Everything else is just variants using those engines, and the vast majority of those variants (Opera, Brave, Edge, etc) are Chromium-based/using Blink. That’s not a lot of difference. If you really want to get away from chrome, your mainstream option is just Firefox. Unless you’re on a Mac, or iPhone. Where you can choose between Firefox and safari.
Doesn't Firefox use Quantum now? Gecko is what used XUL and it was buried when they switched to WebExtensions.
Pale Moon uses a fork of Gecko called Goanna.
SerenityOS has an independent browser in the works, and netsurf is still around.
There are options, but people have put most of their eggs into two baskets and now we're stuck with things looking mostly the same but some have antifeatures.
I want a browser with uBO's functionality simply built in. Fuck your extensions or other attempts to endrun, Google. Stop it at the source and build request filtering into browsers directly.