Legit though, if you for some reason need to use Reddit on mobile:
Firefox Nightly > unlock the extended addon collection support > create an addon collection with uBlock, res, and Old.reddit redirect > import to Firefox Nightly.
Boom. Old.reddit on the phone, it never ever sends you to the mobile site.
Now mind you, it’s a janky user experience using old.reddit on mobile, and they’ll sunset old.reddit soon, but if you absolutely need it, there ya go.