These use a normal GS electric/Lamb brushroll motor similar to that used in many power heads. It’s not the motor, it’s actually the belts. Royal/ Dirt Devil is not very well known for having the best quality belts.
Honestly, that weirds me out too. I would usually rather put stuff like this in the contemporary section, but it gives the option to label it as a 80s/90s post and this particular model is a 97.