Right now the Xbox gaming pass sells for $9.99 per month. Last January there were some 18 million subscribers and Microsoft is hoping to bring many more players. To realistically recoup the investment, Xbox will need 500 million accounts which is still a lot of blue sky.Microsoft is making a pile from Azure so they can afford to develop the game pass concept. Still the Xbox One and above market is hardly 200 million so substantial numbers of new consoles need to be sold and demand is not that high at present.
Many first party games now cost as much as $100 million to develop. So 18 million subscribers is not meeting the payroll for first party games. Xbox spent a pile tp develop Halo and games sold in the first week well above the development cost. Sadly many games launch and only earn a fraction of the development cost.
At present most games on the Xbox pass are catalog games which have already earned as much they are going to and the Xbox pass simply adds some cash to the coffers.
Undoubtedly Xbox is spending a staggering amount of cash to promote Xbox and the game pass. Other console backers have deep pockets but nobody is slugging it out with Xbox yet.