Yeah, and that’s a very large volume of air for most interesting payloads. You have to move the same mass of air as the vehicle mass plus the payload mass. That’s a lot of air. Running UAVs indoors in a normal sized room quickly starts large air currents that have to be faught by blowing more air…
All of them.
Even with a 10x increase in battery energy density, you still need to move the same volume of air to generate enough upward thrust for a given weight.