>I'm looking for a career fixing problems caused by tech as a techie.
Oh, I thought you were looking to do something for the good of humanity. I'm afraid all the paying jobs are antithetical to that goal to varying degrees.
>How do I make some FOSS which addresses being lied to by Google AI?
Work on your own model, or at least a framework where other people can make their own models. The biggest issue with AI right now is it's expensive to run locally, thus entrenching cloud interests. I suspect that unless hardware gets insanely cheaper that we'll have domain specific models to serve that purpose.
>How do I make FOSS that makes the web a more pleasant place to browser without popups and broken back buttons?
Ghostery did a pretty good job with this. So much so that the advertising companies are struggling with ad blockers. For broken links, perhaps a wayback machine plugin that renders the latest historical version of said hyperlink.
>How do I turn FOSS into a career? I've worked at companies who use FOSS and contributed both on the clock and off, but it was never primary way I made money.
The only models I know of that work is freeware / premiumware and/or support contracts.
>What makes me so frustrated is that these things are getting worse, and I feel powerless to stop it.
You (we) aren't powerless, but perhaps overmatched. The nice thing is tech can really disrupt entrenched interests. Linux is a prime example. Most people don't remember how powerful Microsoft Windows was in the 90s. They still are but at least there are viable alternatives, particularly in the server sphere.