The surface area of stuff that an OS has to do today is absolutely massive, and the dependency graphs are poorly understood even by the engineers who work on those systems. Innocuous pieces of functionality have a way of becoming load-bearing over time.
If you ran around disabling random bits of functionality in Windows because you wanted to reclaim some resources for your games, you'd probably wedge the OS, cause random crashes, and prevent your games from even launching. Like you might think "Well my game doesn't need Bluetooth, I only use a wired controller!" but I would not be surprised at all if yanking out the Bluetooth stack from the OS caused random crashes and hangs.