It absolutely sacrifices firepower. Apart from its poor damage (which I can concede is a difference of opinion) any damage it takes is not only sacrificing its firepower, but the surmpioneer's too. Every second it spends repairing it (which was double hit during the patch that nerfed their repair speed as well as increasing kubel HP and lowering Armour), is a second its not using its early superiority to push.
As you said, OKW is about an aggressive start, cant do that if your surmpioneer is buzy repairing.
On a tangent, the only late game role it has is building it and throwing it away to decap a VP or cutoff.
sturms can easily repair it whil capping, soemthing they should be doing anyways.
sturms also repair quite fast. it takes literal seconds to repair and the combo can easily take enough ground to be worth those seconds. i feel a little silly here having to explain the basics im not going to lie.
all units have down time when they take damage, infantry and vehcles. the kuble has the power to make up for that down time by being far more mobile than most things in its time and the only of such that can cap and fight.
you repair after you pushed the enemy off. its fairly basic really...
Yes, change its role seems necessary.
How many pros or anyone in general use the Kubel. It is certainly not a highlight if you have to compare to a Universal Carrier. It offers more of an aggressive start and even later on. It does cap but certainly bleeds manpower in the beginning, giving you a better aggressive play.
Kubel caps, there is really no other pros but more cons if you compare.
Take away Cap
Increase Price
Buff AI/DPS
because volks are god tier and what gains you get with the kuble arent currently worth the distance that volks will take you. thats why i want shared vet on the kuble so it can continue to serve even when its too dangerous
you shouldnt be comparing it to a UC anwyas, the UC has the same price difference as volks and penals, more than the difference between grens and tommies. the difference in price between a pak40 and a rak43. do we need to argue about which one should be leaps and bounds greater in that scenario?
kuble and bren fill different roles (despite you wanting them to fill the same) bren is a fighting vehcle, kuble is a utility vehicle that can fight. they have sturms and volks behind them, you cant have a super armoured mobile sniper behind cheap volks and powerful sturms, there needs to be some risk for the reward.