They stop reporting exact figures when they don't do well.I think a lot of people have their heads in the sand over it - and it's easier to be unaware when Microsoft doesn't report that kind of thing in depth in their financials.
Like, every financial report we know exactly how many PS+ users there are but the number of GP users is a mystery. I think it was 2-3 years ago that people were speculating it was nearing/broken through the 30m barrier but the last estimate was below that. Part of their push into TV apps and that Keystone device was to try and reach more people who won't buy the console but maybe would get GP to play on the TV, but the TV app is still limited to one provider and the Keystone device got scrapped - I'm sure it'll be back in some form sooner or later.
I have no idea if Gamepass turns a profit or not. I suppose that doesn't really matter. As long as it does one day.