If you absolutely have to read something from reddit and it throws this, just switch to the desktop site instead of mobile.
Hilarious how their logic completely breaks down when doing that, and they don’t even care if you know.
They want you to download the app so they can collect your data and push ads that can’t be blocked with browser extensions.
Those who use old reddit to get around it wouldn’t likely get the app anyway, so why even try blocking it?
I don’t know what you’re using but request desktop version in Firefox on Android works fine. Tried it just now.