Absolutely. It has to stand on its own feet. Yet the only reason Mozilla is being kept alive is due to Google paying them to be the default search engine as part of a deal which is where the majority of their revenue is from. [0]
Funny how their mission in "supporting internet privacy" also somehow means we must have deals with companies with the likes of Google who don't believe in Mozilla's own mission in order to survive.
[0] https://www.mozilla.org/en-US/foundation/annualreport/2018/