Google has plenty of clout. But they don't do things well. They never have. They way they first implanted Wallet was, as usual rushed, and poorly thought out. The phone companies were working on their own systems, and Google didn't think it out properly. If they did it correctly, the carriers couldn't have turned it off. But they allowed it after the first year, and still, people haven't used it.
Essentially, no mobile payment system can become successful until Apple does it. That just the way it rolls. Not because the carriers won't allow it, but because Apple does it properly, gets the partners, and has people who own products who want to use the features. In addition, Apple product owners spend more money, and on average, are more successful financially.
This is a choice Google made in the beginning with Android. They were so terrified that the iPhone, and apps, would kill their ad model, which it is in mobile, that they wanted their own platform to ensure that their ads would still be served, whether directly on the web, or in apps. Interestingly, their financials show that they make 75% of their money from mobile from iOS. You know they're not happy about that.