“Because green skyscrapers and high-rises are a bullshit non-solution to serious systemic problems.”
“But if you want greenery on a building nonetheless, do I have an idea for you – a portable, modular, scalable solution called ‘potted plants on your balcony’.”
The reality is plants are beautiful and greenery is good for the environment. So as long as you do not put literal trees on a building it should be fine. Also modern tall buildings have cranes on top for facade work, window cleaning and so forth. So caring for plants is certainly possible. Also those green skyscrapers basically have potted plants on them as well.
Plants also come with a lot of benefits. They cool the building when it needs cooling by providing shade and water. If you are in a colder climate and the plants you choose loose their leaves, they even allow sunlight on the facade, when heating is most needed, while shading it in summer. Plants like wine, which can easily be green on facades have useful fruits. As do many fruit trees, which can be grown from the ground floor in espalier fashion.
Then we have roof gardens, which only have been in use since 600BC or so. They work and are nice.
Also really import everybody has to look at a building and especially when you are building tall, they should make sure the building is beautiful. Plants are beautiful and are a great option for decoration.