It definitely varies too much to use a blanket statement like that. Historically, Intels are the way to go if you value performance over cost, and AMDs are the way to go if you value money over performance. If you're building on a budget, go with a Ryzen; if you're going for value, an i5 is probably a better bet than a Ryzen; if you're going for best performance, Ryzen's don't come close to the i7's. It depends what you're shopping for.
Sorry, but no. Ark is a VERY demanding game. Even with the "excellent" or "magnificent" builds you'd get frame drops on full settings. I think if you played on low settings you might hover around 30-40 fps, but there would still be drops bringing it lower occasionally.