You're comparing apples to an apple orchards.

Mozilla produces browser, email client, and calendaring apps (among other things.)

Mozilla's nonprofit arm engages in tech advocacy and betterment work, including sponsoring fellowships (looks to be about thirty this year) and innovation awards. The work they fund covers a mind-bogglingly vast range of topics in the humans-and-tech area: https://foundation.mozilla.org/en/what-we-do/

Brave is a browser run by a guy who has done just about every slimy thing he can think of to make money, including donation scamming and affiliate-code insertion.