While we all want AMD to be competing in the high end, we know it's not going to happen anytime in the next few years. Vega 20 will arrive ~Q1 2019 but will be a professional product. Navi is expected mid to late 2019, but is targeting a performance level close to Vega 10. By that time, it will be competing with GTX 1060's replacement "GTX 1160", so only competing in the lower mid-range and downward.
We've seen the hype ahead of Fiji, Polaris and Vega, and we know how they turned out. Now once again the forums heat up, this time about Navi and shrinks of Vega, and the usual Youtubers pour fuel on the fire. It's astounding how much faith some put in TSMC's 7nm node to solve all of AMD's problems. Even if we assume TSMC 7nm is free of the problems 40nm/28nm/20nm/16nm all suffered from, we might hope for something like ~40% improved efficiency or ~30% more performance(through higher clocks), but that will be towards the end of the 7nm lifecycle, not Q1 2019. And AMD will have to choose between better efficiency or higher clocks, or a mix, but they can't get the full potential of both.
People should remember that a GTX 1080 performs about 80% better per watt than RX 480 or RX Vega 64, so just a die shrink will not be enough for AMD to keep up. "Consumer Volta" would easily beat a die shrink of Vega, and would probably do well against Navi too, despite the advantage of a smaller node. Also remember that 7 nm will not ship in massive volumes in Q1 2019, so AMD will have too choose which chips to prioritize.