They have had working electric busses since the 50s
I have ridden lots of them, and they did not even need batteries
No batteries.
Where does this electric bus you’ve ridden get its electricity from? A suspended wire that has an electrical current? If so, then it would be a trolley of some type, would it not? If so, then, for the most part, the power for that bus comes from a FOSSIL FUEL power plant.
They were displaced by more popular and useful ICE vehicles.
To the EV evangelicals I say, "Free Beer Tomorrow."