>>1573042>they require centralized ownership of vast amounts of propertyThe unfortunate truth. A shame because a network of raised walkways so pedestrians never had to be around cages would be the most baller shit ever.
Instead of forcing a monopoly on ownership or making developers work together, how about put a new city law in place that all new towers must have some sort of interface or opening in the building facade on the 3rd story or so that would allow for a pedestrian bridge to be constructed in the future? The city government could cover the cost and installation of bridges, developers just have to make their buildings compatible with them.