You're presenting this with ironic swipes like "bad things like ask for more money", but it's hard to read this description as anything but straightforwardly more efficient.
If there are few downsides to centralizing game engines, and the need for engine work is inherently cyclical, why should we want engine work to be internal and non-cyclical?
I really don't know much about game engines so maybe there are real downsides to that approach, but the way you've laid it out makes it seem as if Microsoft made the right decision here.
Measuring value that way is precisely what “from a business perspective” means. Things can also be judged on artistic or technical merits, among many other perspectives.
For a game a reasonable definition of value might be based on how well people like it or how much it entertains then (as if that could ever be measured).
Try actually playing a modern Doom game and then a modern UE5 game or look at some benchmarks. UE games mostly run like shit, whereas Doom/idTech games are the smoothest in the entire industry.
If there are few downsides to centralizing game engines, and the need for engine work is inherently cyclical, why should we want engine work to be internal and non-cyclical?
I really don't know much about game engines so maybe there are real downsides to that approach, but the way you've laid it out makes it seem as if Microsoft made the right decision here.