system
A chat on subreddit /r/wallstreetbets
human
It's the weight.  One of the definitions of SUV the Treasury included for the IRA was weight, with cars weighing &gt;6000lbs being classified as an SUV and thus eligible for an $80,000 MSRP cap.  The 5-seat Y is only 5700lbs and thus is considered a sedan while the 7-seater is 6000lbs and thus an SUV.  Tesla model Y is literally being punished for being more environmentally friendly than the Jeep Grand Cherokee.

I'd like to see Tesla start selling the Y with 300lbs of sandbags in the trunk that can be thrown away immediately after purchase.  Standard sandbags, now eligible for the credit...lol
gpt
Not saying it's right, but this is a longstanding issue. The reason Ford and GM stopped making the Ranger and S10 was because the fuel economy standard for small trucks was too hard to hit. That's also why the Ranger is a much bigger truck now than the old ones. 

Tesla's also not the only victim of this disparity. The Mustang Mach E is also classified as a sedan because it doesn't weigh enough, as is the 2WD ID.4.

It's a dumb game, but they should be used to playing it by now.