Kubel does not require tech cost and it is allot cheaper.
Kubel spam was a problem but the unit is hardy used now, the 221 is simply not cost efficient.
It's not meant to be. If it were, you'd see them spammed. Imagine playing against Soviet T1
as USF.
The purpose of the 221 is to provide some helpful extra firepower and anti-team weapon support before the 223 upgrade unlocks. The 223 upgrade turns it into an anti-infantry 222 with a load of useful support abilities. It can also turn into a cache when you're not using it to pay back its fuel cost.
It is, first and foremost, a utility vehicle. If you'd rather an anti-infantry shock unit, build the Luchs.
And making it useless make revamping the commander pointless.
There's a world of difference between being useless and being a shock unit. The 221 is useful if you have it.
The 223 is simply a more durable OPEL truck with 30 fuel cost and 4 pop and thus inferior.
Opel trucks aren't fast, armoured and armed.