With VTOL buses (vertibus) solely driven by thrusters you are a slave to a variation of the rocket equation, i.e. you need a lot of power to lift by thrust alone, you need big engines for that and those weigh, and guzzle a lot of fuel, so you need even more power to lift those bigger engines and the extra fuel.
I'd embrace the steampunk and have steam catapults (pic) provide the initial vertical push, while also charging something sufficiently steampunk, like a flywheel, on the vertibus. Heat up a big ceramic foam to red heat, add water, funnel the resulting steam into a big cylinder, which operates, with one titanic thrust, the catapult and the flywheel-stirrer (or the air-compressor, or whatever form of energy the vertibus takes). Overspill and the release from the cylinder will form a mighty cloud, from which will hurtle the vertibus - expertly/electronically piloted to touch down at the precise apex of it's arc soft as a down. Possible perturbations by wind or error are controlled by airfoils, thrusters and/or the rotational inertia of the flywheel(s).
Essentially a steam cannon with guided (and manned) munitions. The loading of the short-term energy storage gives you ample leeway to start the steam-show before actual liftoff.
The cannon's length depends on what accelerations you think the passengers can stomach, and what height you want to traverse : https://www.desmos.com/calculator/on4xzwtdwz
To descend, the vertibus drops and uses the steam catapult to decelerate.
If steam is actually too Victorian for you, the catapult might operate with a magnetic coil, cooled with liquid nitrogen, which needs to be boiled off, because the coils get overclocked and need the extra burst of cooling at the moment of start/touchdown. The cloud will still be mostly condensed water, so the caveats regarding radar and visibility apply.
Real VTOL (excluding usage of scify-y stuff like antigravity) either needs thrusters or some (helico)ptery contraption, and it needs them during the whole flight. Thrusters go by F=m*a (resultant thrust is equal to the expelled mass times the acceleration of this mass), so you need to either move a lot of mass (which needs to be taken on the flight, requiring even bigger F, see the devilry of the rocket equation) or high acceleration of said mass, resulting in high velocity of the expelled mass - this in turn means supersonic gasses, which results in copious amounts of noise and mechanical danger. - (Helico)ptery solutions could be made silent, but that would require huge areas for the lifting surfaces, which might be impractical for city use (- also, no apparent use for fog...)
The cannon/catapult solution could be made virtually silent, and thus city-friendly, provided the vehicle never exeeds the speed of sound, limiting the solution to heights of a few hundred meters.