I don't know about hard requirement
But I don't want to run wires. So rear view camera is iffy.
That's why I really love that security 360 style camera but everyone said it sucks so I guess I shouldn't pay way too much for a way too little.
I won't have any passengers so I really don't give a s*** about the interior view. But if the camera gets a cop while I'm simultaneously audio recording on my phone that's a benefit. So that's what the interior view would be for.