That's a lie sir. Brave blocks ads out of the box. Vivaldi also has ad block filters. You can add custom filters to both browsers. Also edge has shitty ad blocker. Kiwi browser supports almost all chrome extensions. Basically almost all except chrome and still you can block most of the ads using correct dns server.
Firefox is as much botnet as others. Full of telemetry, diagnostics, pocket and other shit. That's why there are secure forks. Firefox in stock form is as much botnet as others. Also firefox is selling out to the same google so don't pretent it's better because it's not.
Accepting a ton of money from Google to make it the default search engine isn't selling out to them. Any concerned user will know how to change the default.