[cucumber3732842]

Will never happen. They'll lobby to create permitting process so absurd that you can't develop new sites in order to preserve the value of their investements.

And the usual demographics where support for such boondoggles throughout history is found will cheer for it because they'll dress it up in environmentalism and 15-min cities and whatever the other issues of the day are.

[mbg721]

The lower-friction result is that the offices become huge apartment buildings with reverse-commutes to the suburbs, hoping the "stuff to walk to" survives. There are issues with that too, like plumbing and windows.

[red-iron-pine]

most of those issues will be very expensive or insurmountable for most high-rises -- a non-starter

you're basically rebuilding from scratch at that point.

[mbg721]

Maybe this is a US perspective, but those are attractive properties.