“Believe me, there would be nothing safer than helicopters about air taxis. All the same problems would exist.”
No. The main problems with helicopters do not exist with EV taxis.
With multiple rotors there is no need to counter the main rotor torque. Gearing related to the main tail rotors is a high failure path resulting in fatal crashes.
One engine failure on a helicopter results in a crash. Not so with EV taxis.
I think the problem will be them running into things, like other taxis, planes, power lines. Unless they use the present air control system, which would greatly slow down any adoption.