I noticed the difference in my xbox controller vs playstation. My woman had to keep hers plugged in because the battery was at end-of-life, I kept a set of rechargeable AA's and used them in my mouse, xbox paddle, razor...I forget what all else.
Nope just greedy fuckers being greedy. In devices like phones it kinda makes sense from a space efficiency standpoint but most devices its simply so they can take ur money when u need a replacement.