How many people seriously pay $17 for EA's release cadence or $18 for Ubisoft's? Those aren't serious products and simply exist to churn revenue from whales. They exist because they aren't a threat to game sales and a company like EA is more into that Ultimate team monetization than anything anyway. Game Pass is far more mainstream than those services and would actually threaten to cannibalize sales which is why when CoD was added it changed entirely.
Either subs cannibalize sales or they don't (clearly they do) the question is would you or most any company rather 3-4 months of subscriptions (higher churn rate estimate) or a 1 time purchase for the same amount of users?
I'ma tell you almost everytime any established business is gonna take the subs unless they are in dire needs for upfront revenue for some reason.
Everything about subscriptions is superior for the seller, outside having to constantly improve and or provide content. It just so happens that's Microsoft specialty in general so they already ahead of the curve.