As time goes by range and charging will become less of an issue, as I’ve said previously if you compare battery technology to a human lifespan battery technology is still in the womb.
BMW reckon they will be producing BEVs with over 500 miles range in a year or two they are also at the forefront of wireless charging which is ideal for taxis sitting at the rank.
Of course the elephant in the room is with autonomous driving around the corner there won’t be any taxi drivers.