Underground housing, underground businesses, etc. Would that be better for the environment + possibly save on energy costs? Also possibly safer in certain scenarios like tornadoes etc.
Potential issues that immediately come to mind are ventilation, earthquakes, and flooding. But it’s not like underground dwellings/basements/etc. aren’t a thing, so maybe those issues have been addressed in ways I’m not familiar with.
Both of your scenarios seem to start with an empty landscape. When I heard “move the ground level up” I took that to mean that we are starting with an existing cityscape that has a ground level, and everything must be elevated.
If we’re just talking pure theoreticals built on a tabula rasa, okay then. Like you said, everything can be hand waved away.