Batteries do not have the energy density required for flight. VTOL is the most demanding way to get airborne, requiring twice the power of a conventional takeoff. Lots of small diameter rotors, shrouded or not, are much less efficient that a single large rotor at producing the lift needed for vertical flight.
Multiply all these obstacles and you get a system with at least a hundred to one disadvantage vs helicopters that began flying nearly a hundred years ago. How does this kind of thing get funded? It doesn’t burn kerosene at point of use.