In an ideal city, the cars would all be underground, and pedestrians would walk the ground level automobile free. Few trees would need/require cutting down, and more trees should be planted. With Times Square, Herald Square, Grand Central Terminal, Hudson Yards, High Line, and their vicinity all becoming fully pedestrian in the next two decades, and with NYC aiming to replant 1,000,000 trees with the goal of replacing all the trees cut down to develop Manhattan, then it begs the question: is it worth it to make all these roads, and connections between forests? I like the idea of a really tall building that could support an entire city but it being surrounded by trees, as opposed to many buildings forming a concrete city, and a few small parks. NYC has opened its eyes. Other North American cities are opening their eyes. Shanghai is not perfect, but at least they are carefully developing their major structures and not displacing many trees in the major cities.
Cities aren't just promoting the planting of trees on every concrete block for no reason. There is a reason. Shanghai is preserving the Pudong forest as much as possible, while building cities in the sky.
Cities in the sky is a 21st Century concept, and a concept that works.
This below works.