They are better in the long run when combustion engines have reached their end of life and needs to be changed for something. But replacing a combustion engine solely to get an EV is a waste of energy and material. EVs are heavier and require energy to move, usually a single occupant. Tire wear is also responsible for pollutants in the air and in the water, and because EVs are heavier, they do that faster.
Parking lots generate heat islands, etc.. Buying a new car is inherently bad for the environment. We need more traditional means of transit and much much more active transit plans, not more cars!
WE CAN'T BUY OUR WAY OUT OF THIS WITH NEW GADGETS AND TECHNOLOGY.