Using Firefox more will put Mozilla in a stronger position to negotiate a better deal, whether with Google or someone else. Worst that could happen is Firefox turning into some kind of boutique browser for connoisseurs willing to pay. That's uncompetable.
They might be able to raise revenue using other innovative methods eventually, but that won't amount to anything if we aren't using the hell out of their (very good) browser.
Google doesn't even need Mozilla to increase/maintain their search market share. When Firefox's default search engine was changed to Yahoo! in the U.S., many users switched back to Google [1]. Also, people who care about privacy use things such as DuckDuckGo anyway.
[1] https://searchengineland.com/report-yahoo-search-losing-fire...
who else is going to do it? firefox still has the best chance.
the more popular firefox gets the easier it should be to get alternate funding.
a premium browser would not sell. browsers are like operating systems. they only provide value through the content snd applications they enable. browsers are no longer interesting in themselves. noone actually cares. the only thing that matters is, how many websites are not broken.
that's why edge is building on chrome. it's the only way to ensure that they stop breaking websites.
brave has an interesting business model (and i am not saying i like it) by motivating its users to pay for content and taking a cut.