I built my private version of Infinity for Android. The steps were 90% automated. They were in a Reddit thread like this one (I just pasted the first thing I found now), although I don't know if the build process still works. https://www.reddit.com/r/Infinity_For_Reddit/comments/1izm7c... -- you have to side-load the app, which is a little tricky because you have to load it onto your phone. I think put it on a private Google Drive.

Maybe similar solutions exist for iOS, but maybe the side-loading is not as easy?

Anyway, on Windows/Chrome I use uBlock Origin and never see any ads in Reddit online. There was a lot of drama about reddit selling out in 2023 (I was sad to see Infinity die), but there are tech solutions to avoid its enshittification.