In this particular case, what problem would open platforms solve? The laws in Pakistan still exist and the social problem is not addressed. Or are you implying that Apple and Google should be on the hook for solving religious problems in other countries? If so, I think wanting companies to engineer social behavior in other countries is a dangerous path bordering on the unethical (IMO).
But having said all that, whats stopping a country from simply blocking their hosting servers? Ultimately, the app has to be downloaded from somewhere. Okay, so then you move to a P2P system, so then the get their ISPs to block that,etc ,etc. It's just whack-a-mole.