Your link is about bypassing the 2k Launcher, not Steam.Reddit user avonhungen says that it is here on a Mac:
~/Library/Application Support/Steam/steamapps/common/Sid Meier's Civilization VI/Civilization VIand this Windows-centric Launcher bypass page shows how to ask Steam where the executable is instead:
Bypassing the Steam launcher allows running Civ VI directly. That, plus galad's v-sync comment, seem like a good path forward which I'll try shortly.