The documents you linked to show that 2022 they have a billion and something in net assets 513 million in cash (up from 378 in 2021). Cash flow from operating activities was 147 million in 2022 and 197 million in 2021.

So according to the documents you linked, Mozilla is doing extremely well financially.

Also according to your documents, they spend the vast majority of their money on developing Firefox.

If they continue to grow alternative revenue streams as they have in the last couple of years, they will be in a position to develop Firefox without Google funding in the intermediate future.