What is the biggest (or second biggest) barrier to EV adoption? Price. And what brings down the cost of goods in a market? Competition. Ergo, if you want to drive down the cost of EVs long term with subsidies, you foster competition, not steer subsidies toward the market leader.
And who is talking about Bubba's garage. There's only a handful of companies that would qualify for EV credits, and none of them are mom and pop shops like you are hallucinating. Hint: You got to actually have an EV to sell if your customers are going to qualify for the credit.