I hope this will happen soon. NYC passed a green roof law in Nov. 2019 that requires all new or extensively renovated buildings to install gardens, urban agriculture, or solar on their roofs.
Loads of SF streets are hyper industrial and have no trees. It's strange what an effect it has. Walking through SOMA feels weirdly like being in a concrete video game. Walking through my neighbourhood in Glen Park is lovely and charming.
I work near the new building at 1550 mission and they've put trees down in front of that building and the street is instantly nicer.
Any city really. Imagine gardens at rooftops and some window vegetable gardens being more common place or balcony gardens.