Induction motors have quite large diameter rotors and substantial stators so they are quite large. The "heatsink" doesn't contribute much in size. You could replace the motor in the drill press either with a servo plus its drive, or a 3-phase motor and VFD which would be the same size or smaller for the same power as the single phase fitted. Not sure which would be cheaper. Having variable speed and reverse on a drill is useful - machine tapping at low speed with instant reverse is very useful. I don't know why you are concerned about power for a drill, 500W should be more than you are likely to ever use with any drill you could fit in the chuck.