crackerdog, I'm pretty sure that you have this figured out, but I wanted to answer just for my sheer interest in the topic...

an electric car would because an electric motor delivers a great deal of torque.

But if you make the motor a bit on the small side, then multiple gear would be necessary.

Back to bicycles....steep hills have a way of making an electric motor on an ebike too small.

The solution?

go for a bigger more that naturally has more torque ( but you'll kill your battery faster)

or

go for multiple gears.

or

go with one gear that is lower, but that will effect your top speed.