Ok, what if you don’t use paypal. Or if one app uses pay pal, but another wants you to use some other payment solution. You’re still stuck registering to new services and sharing your CC info. So now you also have to remember what service is used by whatever app you are trying to cancel billing for.
You might just as well insist on never linking up your Google account with payment. This might not apply to a random pay to win candycrush clone, but Spotify is enough of an outlier they they likely have quite a few subscribers (or would be subscribers) who never accepted their phone as an app store payment mechanism. I know quite a few people who I'd suspect to be far more willing to hand over they CC data to Spotify than to Apple/Google.
