Roofs and walls at sun absorb heat and irradiate it later inside the home. Louvers just block light inside but can not save from having a roof too hot.

Houses next trees instead are shadowed some hours a day, they are more fresh inside and heat less, so are much cheaper to keep at habitable temperatures in hot areas.

Trees are also great blocking street noise and removing contamination.

We just can not remove plants from cities without suffering negative collateral effects