https://www.youtube.com/watch?v=ex4Qg-gkLNg&t=530

By car battery standards, an absurdly large amount of energy. And it's released in a pretty inefficient manner. So not a good plan for EV range.

I don't think you could reasonably use them on the road without harming people around you either (though Musk's target audience may not be very concerned about that aspect).

I think it works for track usage / showing off to your wealthy friends. I have no clue how the flying version would work control wise, as you'd need to plan the entire flight ahead of time so it could verify it's possible (before you take off down the Grand Canyon and run out of gas a few seconds later). Probably one of the reasons it's not being sold to everyone.

It's a supercar, being practical isn't the point.