Funny enough, we have them downtown. They've flooded a few times due to the monstrous rains we get here (see hurricane harvey).

I think Minneapolis figured this out the best with a downtown connected by skybridges on the 2nd floor connecting tons (most?) of the buildings).

>Y'all need pedestrian tunnels.

Yeah, and? Most people also find pickup trucks excessive. And yet, they are the most profitable vehicles on the planet. So much so that Tesla wants to make one. There's a whole world outside the urban bubble, for better or worse.