Maybe they just don't know any better
firefox is debataable
Name a better open source browser built from the ground up that isn’t backed by big tech, I’ll wait.

Ladybird is on the horizon.

Also Firefox isn’t built from the ground up I don’t believe. It’s based on Gecko which iirc was based on KHTML. idk i can’t fully remember don’t take this as fact. i use firefox and prefer it to chomium based browsers but Mozilla has been making really weird moves lately around AI that I think is very unnecessary.

Chrome and Safari are built from forks of KHTML WebKit, not Gecko.

Firefox was born out of the Mozilla project.

That came from Netscape?
Ladybird is also making weird moves around AI and I feel obligated to mention fascism
Ladybird adopts Rust, with help from AI - Ladybird

We're adopting Rust as our C++ successor language, and using AI agents to accelerate the transition.

Ladybird is not becoming vibe-coded, the AI generated code is being tested and refactored all the time, it’s not straight up slop like what most junior devs do now.
Firefox is literally backed by big tech though?
there are none but that doesnt mean firefox is good dont settle because everything else is worse
Just because there is no better open source browser doesn’t mean it fits the description of OP’s list