The fact that this is or isn't happening is basically unrelated to inventing new stuff. It's almost entirely a political issue, not one of engineering.

land use and design issue more than anything.

ramps have been around for a long time, and are well known to take up a ton of space. especially if every propery gets its own ramp rather than all the properties on a block sharing the same ramp system and having a common porch

The two are not unrelated, and perhaps the inventiveness and energy of the latter could be applied to affecting the outcomes of the former.

It's very much related because the technology provides an excuse to ignore the infrastructure problems even when it isn't good enough.