There are other mobile browsers which incorporate adblocking directly (though not extensions generally).
The Einkbro browser, optimised for e-ink devices (as the name suggests) is one. I believe Brave does as well.
As much as I'm a fan of Firefox (using it now on desktop), on my mobile e-ink device, Einkbro's optimisations make for a vastly superior browsing experience.
DNS blocking has some nice qualities (simple! efficient! app agnostic!) but it is absolutely not a replacement for something that can inspect and modify the page itself. That has TONS of additional usecases beyond "replace ad image with blank space".
I wish I could switch to FF, but I still need PWA support + rich media notifications for a web based music player I wrote.
https://play.google.com/store/apps/details?id=com.kiwibrowse...