I realize I'm being imprecise with my words. When I said that AMD might beat Intel, I meant that AMD might release processors that are better in benchmarks than Intel. I'm speaking within the extremely narrow context of what I'll dub the 2016-202X Processor Wars. You're speaking of the big picture, which I don't feel qualified to speak on. I simply don't know enough to argue that point, but I'll accept it.
What I do know is that AMD knows it can't compete with the whole of Intel (even with TSMC's help), so it focuses on a narrower segment, Intel's processor division. AMD found an opening in the market, and it exploited it, though that's probably gonna change, now that Intel's announced that they're going to use third-party foundries as a way to shore up their (lack of) 7nm fabbing ability. Intel, a company that wouldn't have been caught dead outsourcing its processor* chips 5 years ago is doing it. I suppose that AMD, as a fabless company, means that they're flexible. They can choose whatever foundry fits their needs, be it TSMC, GlobalFoundries or whoever**. They're not stuck if their in-house fabbing suffers from delays like Intel. Intel could leverage that same flexibility by outsourcing.
*They did use third-parties for low-margin stuff, don't get me wrong, but their processors were almost entirely in-house.
**And they did, GlobalFoundries manufactured the Ryzen 1000 and 2000 CPUs, and the Ryzen 1000, 2000 and 3000 APUs. If TSMC (who make the 3000 CPUs, and the 4000 APUs) falls behind, I'm certain AMD will choose another foundry.