Steam has released the details of its hardware and software survey for January 2019. In terms of PC video card usage, Nvidia absolutely dominates the chart with 74% of users having a GPU from the green team. The GeForce GTX 1060 is the most popular graphics card, while the highest-ranked non-Nvidia product is AMD's Radeon R7 Graphics in 14th place.
https://www.notebookcheck.net/Nvidia-GeForce-GTX-1060-tops-Steam-s-GPU-survey-while-RTX-cards-and-AMD-s-RX-Vega-make-an-appearance.407236.0.html