Yeah I can think of a few. That sort of influence is one, benefiting advertisers is another, positioning themselves to get a cut of all transactions is another. Is there an alternate universe where in order to get your content in front of users, it has to be AMP and in order to be AMP, it has to meet a new requirement that all payments must be done through a payment framework that lets google control the user experience (“purely for the end users’ benefit” of course)? Probably.