Every car I ever owned for the first 19 years of driving was a manual. I am 100% a right hand dominate person, except for steering.
On a road like this, which is NOT at all uncommon around here, I will rest just my left hand on the top side of the the bottom of the steering wheel and relax my right hand with the cruise control set to maintain speed. Minor corrections is all it takes to keep it between the lines. I am in the left lane only because I did just pass a truck to make a better photo.
In traffic, certainly it is two hands on the wheel except during a shift.
My last wreck was in 1978 when some dumb blonde decided she did not want to scrape the ice from her windshield, and she ran a stop sign at a 4 way stop, she could not see the stop sign because her windshield was frosted up. I would have sworn I saw her stopping or I would not have pulled into the intersection. Steering wheel hand position had nothing to do with it.
Now I see drivers swerving all over the place because they are texting and not driving. Again, just bad drivers and nothing to do with hand position, except their hands are on the damn phone and not the wheel.
On the track, yea, no doubt, both hands on the wheel, 10 and 3 or so.