Not mine! I use… ah damnit.

This a really interesting point I never considered, but Mozilla isn’t being paid by a ton of different advertisers to not implement blocking - are they? How would we know?

Side note, I would absolutely pay for a browser that rolled everything in without setting it up myself.

Are there open source browser derivatives that bundle such an extension?

Any browser beside Chrome or Firefox seems to only be installed by power users, who also know how to install an adblocker.

What if I'm using safari?

Still true. Apple makes money off adversting just like anyone else. they also get paid obsurd amounts of money to from Google to make them the default search engine in Safari.

Apple's interests are aligned with corporate interests in general including advertising networks.