Analogue control for acceleration, sure.
However, in a car your foot is on the pedal while your heel is resting on the floor. You are bracing the weight on the heel, and the heel becomes fixed pivot point, and then the foot is fine to do precise controls.
But a finger on an analogue shoulder button is floating mostly free, three joints out. You need to use the muscles on both sides of the finger, one to pull the finger in, but then muscles on the back to make it not go too far in. The analogue button didn't have hard enough springs to stop the finger pressing in easily, so you were at all times bracing the finger against itself to put the trigger at the right level of control.
This is VERY different to pushing an analogue thumbstick around with a thumb. There you are resting the weight mostly on the stick, and the movement is under control.
Just imagine if you always had to keep your thumb from pressing down too hard on the thumbstick, or else something would happen that you didn't want to happen OH RIGHT YOU BOTH COMPLAINED ABOUT THAT IN THIS VERY EPISODE.