No my foot is on the floor unless I am covering my brake in preparation for a quick stop due to traffic or other conditions. Why would I keep my foot on the brake pedal?
Yes, what else would you do?
Since I observe multiple drivers accelerating with braking lights illuminated, they keep their left leg on the brakes pedal at all times.
Not a good thing to do, but keeps mechanics busy&paid replacing their pads.
I only used my left foot to brake old British motorcycles and for the left wheel of an antique John Deere.
I think having one half or your brain controlling the front brake and the other half of your brain controlling the rear brake on a motorcycle makes it easier to operate them independently, so maybe the Brits were on to something.