Yes, right off the bat, this comparison doesn't make a lot of sense.
However, the Vega 56 (and 64) are power throttled, and you can unlock this to set the unit to whatever power consumption level you want, and therefore, performance.
People have been getting RTX 2070/GTX 1080Ti performance out of the cards by doing this.
https://www.gamersnexus.net/guides/3...modded-vega-56
Any reason not to? Newegg has Vega 56 on sale for $469.99cdn right now, same price as the cheapest RTX 2060 but with 2gb more ram and with this modding, RTX 2070 performance. I dislike what Nvidia has done to the gpu market (essentially made it a monopoly, and therefore massively driven up prices), and would like to support AMD.