Halo Infinite alledgely had a total, insane, cost of 500 millions. Most top tier AAA first party have a total budget (dev + marketing) of about 100-200 millions (like TLOU2, Cyberpunk 2077 being one of a few exception with 320+ millions). Many good AAA games cost "only" 50-100 millions (Horizon Zero Dawn had a dev cost of about 50 millions for instance)
Here's the link to Wikipedia
"most expensive video games to developp" list. It's incomplete and imperfect but you get the idea. The sum of all these 18 games dev +marketing bugdet is less than 4 Billions total.
With $70 Billions MS could have funded
140 AAA with the insane 500 millions budget of Halo Infinite and make all of them available day one on Gamepass. Or
350 AAA with TLOU2 budget (marketing included). Or about
700 games with Genshin Impact budget for Gaas games. That whole deal is a hubris fiasco of cosmic proportion. MS could create hundreds of new games, innovating and with great quality, no one has their deep pocket to do so, but they choose a different path.