You are missing the point tho. Subscribers to GamePass don't own the titles, so MS isn't exactly losing a game, you are renting it.
They're losing a potential sale. I bought Forza Horizon 3 launch day, I bought Forza 7 launch day. That's already more money than I spent on getting gamepass ultimate till April 2022. Money that microsoft has to share with third parties.
At full price yeah it's a deal, with the insane free upgrade from gold they did, that's their bottom line hurt for a while from consumers who took advantage of it such as me.
But looking at the general £10.99/month price, I can see that it will probably be beneficial for microsoft from most consumers, me however? I will likely pay £10.99 and play through a game rather than the £39.99+ I would have paid for a digital copy before and cancel my sub until the next.
So it depends on the individual consumer, some gamepass might make MS more money than it would otherwise, but some consumers gamepass will actually result in less profit from those individuals.