"Selling your data" implies that your personal details you share with Google such as email, location, websites etc are handed over to third parties to do with as they please which is simply not true. Google's monetisation model is genius as it benefits both parties, the user who gets to use services for free and the advertiser that gets to display very targeted ads to billions of people around the world. Meanwhile the user actually receives advertisements that are relevant to him/her.
So, as a consumer you've got the choice between giving one company all your data that it will only use to determine your interests/buying habits etc and recieve much better ads in return and fantastic free services. Or, you could pay a huge amount more to lock yourself in an incredibly tight and closed off ecosystem that has far inferior services to a company that still sells targeted ads and you still give a lot of your personal data to. The choice is pretty obvious in my view.
And, I'm not saying Google's perfect. Google Wallet isn't great and was a huge flop and no doubt Android Pay took a lot of ideas from Apple Pay, which is excellent by the way, and I hope it can work just as well. But, on the whole, I have absolutely no regrets about being in Google's ecosystem instead of Apple's.