Not only this. MS lost nearly every 2nd party developer that helped Xbox.
Bungie (Departure)
Lionhead (closed)
Ensemble (closed)
Epic Games
Remedy
BioWare
Crytek
Insomniac
+ More (including smaller teams like Swery).
Epic and Bungie both wanted to do their own thing. BioWare got John Ricitello'd with the Elevation Partners inside job shit.
The rest of them were on Microsoft, who chose not to make new contracts for one reason or another. Lionhead and Ensemble were wholly owned, and shut down. The dearth of content from 2017-2021 was a function of them basically retreating whenever they didn't immediately find a lot of success.
The studio slate in 2018 when they started buying was only so small because of the long term implosion of Microsoft Studios prior to the decision to start reinvesting and expanding.