NO!
There are places with no traffic, great visibility, clean, dry, smooth pavement.
We have attained over 100 mph at such places.
In such conditions it would be ridiculous to restrict speed to 10 mph over the posted speed limit.
(At those speeds I worry about tire failure, but they are well below the speed ratings.)
Likewise, we slow to a safe speed which conditions permit.
In icy conditions I have driven only 5 mph -any faster and I could lose control.
Also, in fog, 5 mph with all e-lights off, low beams only.
Any faster and I would not be able to stop in time if someone/something suddenly appeared in front.
With patient on board, we drive much more slowly and gently.