Electric cars can help an overpopulated city have a bit less pollution, but the planet as a whole - not so much, if not worse IMO.
My country now gives incentive for "renewable" power sources. So people with money put dams on small, beautiful mountain rivers, and make small power plants. This destroys the mountain rivers/streams, kills all the fast water inhabiting fish (trout I think is the English name). Even affects the surrounding forrests.
Similar thing happens with wind-turbines - haven't seen it for myself, but was told they tend to decimate flocks of birds, who don't see the fins. They even make them with some whistles, to allow birds to notice them, but then you have noise pollution.
Solar panels - they take a lot of room, and have a limited life span - not sure how eco-friendly their production is.
Coal - no need to even explain that.
Nuclear power plants - these seem like the most eco friendly, in terms of pollution per MW produced. As long as there are no disasters and the waste is stored safely and properly.
All those sources are either time, or/and resource limited. Electricity is produced, then converted to charge batteries. Then converted again to run an electric car engine from the batteries. With losses at each transformation (smaller, or larger). OK, when the electric car is run in a busy street it doesn't pollute then and there. It did use pollution to charge the batteries, but that came from hundreds of miles away. It will affect the ecosystem and the climate, probably, but the busy city street will be a bit cleaner, more "eco".
Batteries need to be replaced from time to time, even the rechargeable ones don't last forever. This also creates some waste, and takes effort to re-use what can be re-used, so there's a bit less waste. But there is waste.
Banning private cars, with good quality public transport and bicycle infrastructure are a sensible, long term option. For several reasons. Same, unfortunately, goes for motorcycles as well. Though we needn't fear, common sense is dead and buried. I would expect my son to get to see cars/motorcycles run by humans outlawed, for "safety concerns" though.