Why is it impossible to leave the parking structure.. the worst design . Zero stars

That is not my experience. I rent many vehicles every month in different states. at the time of delivering the vehicle only they scan the vehicle and ready. Sometimes you just follow the drop off arrow and park the vehicle and that's it. the invoice arrives exact via email. We have never experienced that experience. There may be an issue with the payment card.

Is just a long process.

Yes takes a long time to leave the rental car lot