About 20% of the land of major cities tends to be parking, and it's a big issue because that land could be used for housing. City builders tend to ignore that because it makes cities ugly (in real life, it does too!), but if they actually modeled parking in their simulation, it would have all sorts of ripple effects that would be interesting to plan around.

Parking lots are absolutely everywhere. Some zones just prohibit large ones for historic reasons or otherwise (it's possible maybe you were in one of those zones)?

Visit Nashville, TN (around Centennial Park), Orlando, FL (around the Mall at Millennia) or Jacksonville, FL (around St. John's Town Center) and you'll see what I mean.

A lot of parking in big American cities is underground, and also too expensive to be worth it. Parking lots everywhere though, in my experience

All but the biggest, densest cities in USA and Canada have their centers covered in parking lots and parking structures. There's an effort by urbanist groups to reduce the amount of land used for parking in cities. This resource shows how bad it can be:

https://parkingreform.org/resources/parking-lot-map/