Sorry - b4 sdk - b5 xcode - my bad :-)

Yub - seeing same issue here :-( Super annoying - b5, btw, but your simulator build id matches b5, so guessing a typo...

Can confirm - I have exactly the same issue - Macbook Pro 16" M1 Max running Monterey 12.0.1 and Xcode 13.1 2,5%points per hour or 100%->80% in 8 hours