Various Microsoft game/whatevers on PC were such a shit show in the past (while on consoles it was great) I am probably not alone in just ignoring everything that comes out of microsoft on PC.
1. Free to play. 2. Marketing budget in the 9 figure range. 3. Comes from a long established series with ~20 games. 4. Available on all platforms.
I'd be willing to bet there's more of an appetite for complex games today than when Civilisation was released from an absolute standpoint, just that there's also more people playing games in general so from a relative standpoint there's less.
COD sold 75-80 million copies [1]. Getting 30 million regularly implies that one of third of them are actively playing at the same time. That seems rather unlikely
[1] https://www.gamespot.com/articles/call-of-duty-warzone-sees-...