Not everyone has stellar credit and could do that. Also, each card you open will impact your credit score. Down a bit for the hard pull. Down a bit for the new line of credit. Down a bit for reducing the average age of accounts. Up a bit for reducing percent of used credit. It would be a net down. And after two or three of these new accounts opened within a few hours or days the number of hard pulls will be quite detrimental. But let's say you succeed in opening dozens of accounts before your score and the number of pulls triggers every fraud system around. What then? You have dozens of credit cards and an absolutely horrible credit score. Better not need a new car loan anytime soon. Or a mortgage. Or even a new mobile phone plan or some other new utility account. You would be considered a credit risk for quite a while.
Moving from iOS to Android (or the reverse) only takes minutes. Get any unlocked Android (or IOS for the reverse) phone and swap the SIM card. Boom. Done. Oh, you mean apps? Sure - that might take a little while. Many, many apps are cross-platform and rely on subscriptions which may often be paid outside of the pp Store. You probably have some already - Netflix, Spotify, Office 365, Hulu, and so on. Yeah, there will be some that are iOS-specfic where you would need to find a comparable Android app. There may be a little cost involved in those replacement apps. But, hey, the vast majority of mobile app profit is on the iOS platform, so I have to assume that most Android apps are free or virtually free anyway.