Parking structures are insanely expensive. Like, each parking spot in a parking structure costs like 30X what it costs to build a surface parking spot. It’s a crapload of concrete, and with climate change, concrete ain’t getting cheaper (concrete is extremely carbon-intensive, it releases CO2 intrinsically, not just from power-generation).

edit, since I’m getting downvotes and I assume this post is being read as an endorsement of city-destroying surface parking: The correct solution is just to not do parking at all except for extreme needs and focus on human-scale transportation.