There could be many factors here.
1. These studios seriously over hired during the covid boom years.
2. Due to various initiatives, and said boom years the quality of the hires may not have been optimum, so a lot of dead weight.
3. It is possible that the higher ups view some studios as having become too ideological and toxic, especially in light of current market realities and consumer sentiment, if there's a high number of idealogues, it's hard to change course and culture without cleaning house.
4. Studios have grown so big they've forgotten how to be efficient and spend sustainably with limited resources, plus the sheer size innately introduces significant inefficiencies, bloating budgets and timelines.
5. Failing revenue vs the cost. Microsoft like good margins, their games business has slim margins and they've spent a vast amount of funds that will take many many many decades to make back at the current rate of profit.
6. Ai, both needing fewer staff, and different staff, Ai will mean you need LESS (not none) of the specialised roles, and need more generalists who are multitalented and trained or experienced in Ai workflows (and an open willingness to enthusiastically adopt them). This may mean after substantial firing there may be more, different, hires.