Volks are the worst OKW unit period, and making more than 2 or 3 is an epic waste of manpower, as you will be reinforcing them endlessly all game after every engagement. Better to spend the manpower on LeIG, Puppchen, IR HT, literally anything else.
So why do people blob them? Because newbs don't know what they are doing with OKW, and the people who can't beat a Volks blob know even less.
Joseph

OKW Shrek blobs massacre armor and inf once they reach vet 4-5, heck they're probably the most potent unit for OKW atm with vet working again, long as you keep them alive. Just ask Senior Cruzz and he'll confirm.