It's not a Ryzen "Moment." It was Ryzen momentum. They kept on improving gen after gen until they changed the consumer perspective of their brand.
While Radeon release one good gen, then they fumble the next two gens. And then blame Nvidia's mindshare.
That's what a market leader do , they invent a new market or new features to increase sales and demand or to differentiate themselves. Just like Apple's decision of not including a charger with the phone or the Airpods.