I would say I have big feet, but have wondered if that accurately expresses my problem, as opposed to clumsy feet. I learned to drive on manuals, including a 1936 Chevrolet. (Not practical, but a load of fun.)
I also drove large straight trucks for a year or so before the draft. Even the big Crash Rescue firetruck in the Army had a semi-automatic transmission. But, otherwise cars had manual transmission, heh, heh.
In 1973, i was facing a dramatic life change, ahem. And, bought a 60’s Biscayne or Belair, big thing with auto transmission. Suddenly, driving in town was not a major pain any more. Since that date, in 44 years, I have driven a manual transmission a total of around 250 yards.
For the same reason, big or clumsy feet, take your choice, I have driven with both feet, right foot on throttle, left foot on brake. A few years ago, we had a NYC cable guy come on here, and he said the cable company had all their drivers take training from a driving consultant who taught them to drive with both feet, as I described.
The main objection is that bad drivers who drive with both feet sometimes ride the brakes. That is not because of driving with both feet, but because of bad driving.
Older people have trouble keeping track of where their feet are, and when trying to use the right foot for both throttle and brake, there are odds that eventually a mistake will be made, which results in a large number of people getting run over.
Older drivers should be taught to use both feet, and when getting in the car, to look down and get their feet in the right place, and these terrible accidents will not longer happen.
If someone rides the brakes, require them to install a buzzer, a loud buzzer, which rings when both brakes and throttle are on at the same time.