Firefox has about 3% market share on desktop and declining each year.
And there are plenty of ad blockers on iOS.
Yes but almost all shackled by Apple. Orion Browser is probably the only one I've come across that lets me install uBlock and it actually seems to work. None of the other ad-blocking extensions for Safari have the same power as uBlock as per my understanding and usage.
I use AdGuard Pro on iOS Safari. I generally never see ads. The experience is pretty close to ublock origin on the desktop.
$10 closed source app that monitors everything in my browser. Hard pass.
Classic Apple swamp garden where users have to buy black box apps that are often free and open source in other platforms.