Firefox shipped sandboxing on Android years ago (before chrome) and then removed it. I’m not sure you gain much from it on Android. It eats up ram making performance crap on cheap phones and apps already run in their own app user context to isolate what they can access.
I will never really understand why china’s on these lists. I know it’s because theyre communist and commies = bad, but every other country on their has literally vowed to kill Americans, while china’s biggest crime is making close to as much money as we do.