I don't know why, but I feel Civ 6 is running worse than it should on MacOS. I remember I compared it in Windows and MacOS on the same hardware (my old trusty dual-booting Mac Pro from 2010 upgraded with AMD RX 5700 XT graphics) and the frame rate was much higher in i Windows with the same settings.
This article is bull, two random configurations are compared without any logic. Either you compare the base configurations of each, or you try to match the configuration using some criteria. This article compares apples with bananas, you have lost all credibility.