CivLuvah
Deity
It's not clear that what you or most people on CFC regard as high quality is even what drives Civilization's sales at this point. I also don't think there's a fixed size market and that one game cannibalizes sales of the other.
I think what drives sales for Civ is that it's an established game series. A lot of people buy it because a lot of people know about it and want to get into it.
And yeah, the market for big history games like Civ and Humankind is quite fluid, considering that so far the people who are most interested in Humankind are also those who love or have played lots of Civ, so it's possible that one person can play both games.
I think what he was hinting at is the scale of ambition that Humankind offers on the table compared to what Civ6 has right now (I have to admit). Presenting your game as a direct competitor to Civ is not easy. So far the direct competitors to Civ that I know of are simple mobile games that have passive mechanics.