Yes, but they also have inefficiencies of design and production lines, which need tuned to reduce costs, so they have higher costs initially.The incentive is only reduced for Tesla though (and later GM). It's based on the number of cars a manufacturer sells. The incentive needs to be changed to end for everyone at the same time. Otherwise, all the new players to the EV market will have a $7500 advantage over Tesla.
If the government wants to be fair to all manufacturers, they all need time to perfect their technology and that time is however long it takes them to make 200k cars.
If the government wants to further create an incentive for EV over ICE choice to reduce pollution, then it can be a separate rebate.
But I think it's unfair to say other manufacturers don't deserve extra help/time to perfect their technology, which Tesla had.
Probably would make sense to only support U.S. brands and let Germany, Japan support theirs. In my opinion.