I would happily pay to download Firefox if they removed telemetry, ads, analytics. Security updates could be free, feature updates could have a small fee. Something similar.
There is a way to fund Firefox without user data and ads. Will it be as profitable, who knows, because quite simply, the vast majority do not want to make it a reality and loose what profit, control, or power they currently hold onto.
I’ve always said this about software. Let me license a specific version, with free minor updates until the next major release.
If the new version has something I need/want, I may be willing to buy it again.
I use lots of old software, on my PC and my phone. It works, why do I need the new version? And some, the new version sucks so bad I refuse to upgrade (FolderSync on Android, for example).