Infiniti on the Q50 released the first “direct adaptive steering” which was fancy marketing for steer by wire where no column was supposed to be present. This made it so consumers still had the same feeling, but it allowed for cool things like not having a rod aimed at your body, closed up another point of egress into the cabin for critters and water, and also gave you the ability to have it account for road undulations and wind so if you held the wheel straight even on a windy day it would adapt and steer straight. People however freaked out about steering not having a physical link and so Infiniti added in a column that would effectively reconnect if for some reason the steering ever stopped working. But it ruined the idea behind it. Anyways, consumers are kind of what holds us back. We all think of things having to be done a certain way without realizing there could be better ways of doing something. Side mounted joysticks, like a plane, would allow for people without legs for instance to drive cars. People with fine motor skills could be more precise and software could account for a shake in their hands.

A few companies are starting to experiment with brake by wire and throttle pedals haven’t been physically cable linked for decades at this point. Why do we still have steering wheels like that?

Because the opportunity and severity of failure of the physical steering wheel is an order of magnitude or more greater than any other system that has been replaced by electronic systems in most cars.

I've got an idea, how about we put that sort of control on a submarine?

I think a rotary knob will be more intuitive than a joystick. Input is fuctionally the same as a steering wheel, and more likely to require less specialized training and adjustment.