Your peek memory usage in that render is under 40mb. Try again with a heavier scene (A lot of polygons, large textures, etc) try to get that number up in the hundreds or even thousands. I think the results will be a different story.
According to Nvidia spec sheets for the two cards, the 1060 has a slightly faster clock speed. However, the 2060 has much faster memory. Such a light weight scene isn’t enough to really put that card through it’s paces, and may only highlight the difference in clock speed.