Ion thrusters have atrocious thrust to weight ratios. You can slap more ion thrusters on, but that adds mass linearly. You can't scale up voltage much, or you get current arcing across the acceleration region, and you can't add more ions, because they'll interfere with each other. As far as I'm aware, there aren't any designs that have thrust-weight ratios anywhere near 1.
(For perspective on just how much this would need to scale up, the CAT thruster developes 2mN thrust [0.00045 lbf] on a spacecraft that weighs 2.5kg [5lbs] without fuel.)
In any case, if you're flying in atmosphere, you can probably extract your propellant directly (or just use propellers). The whole point of ion engines is that they're fantastically efficient. This is important when you need to carry all of your reaction mass along with you (and your mass ratio scales up exponentially as a function of delta-V), but not important when you're flying through atmosphere (and surrounded by reaction mass).
Space is the only place where these engines are of any practical use; a combination of endless solar power, no friction, not having to stay up in the air by constantly fighting gravity and huge distances to travel means an engine with a tiny amount of thrust that can run for long periods of tiny with a tiny amount of fuel is useful.
On earth you're likely not even going to be able to overcome friction and start moving.
