@cryptids I did a quick fork of Phanpy (web client) that hides posts with images without alt text.
It's on the client side:
https://github.com/cheeaun/phanpy/compare/main...martinwenisch:phanpy:main
I wonder if this would be an option. It'll be hard to push it to the upstream, as it's out of their scope. But if enough people would use it, I'd polish it with a settings switch and try.
Deployment of the changes here:
https://phanpy.muhu.digital