That really depends on your definition of “sane defaults.” Even a lot of the computer science professionals I work with wouldn’t consider Arch Linux defaults as sane. I picture sane defaults to include a lot more basic functionality that Arch doesn’t have out of box (automatic suspend, desktop environment, lock screen, etc.).
I use Arch for the exact same reason you do though. Once you get past the tedious stuff like setting up your networking stack, setting up idle suspend, etc. it’s nice to choose whatever WM/DE you want and customize it how you want.