The suttas rarely define the “root of suffering”. When they do so, we have desire, relishing, attachment, greed as the root of suffering (e.g., MN1).
We also have the ten fetters of which ignorance is one (AN10.13):
Bhikkhus, there are these ten fetters. What ten? The five lower fetters and the five higher fetters. And what are the five lower fetters? Personal-existence view, doubt, wrong grasp of behavior and observances, sensual desire, and ill will. These are the five lower fetters. And what are the five higher fetters? Lust for form, lust for the formless, conceit, restlessness, and ignorance. These are the five higher fetters. These, bhikkhus, are the ten fetters.
These are clear and in the suttas. From these,
can one assert “ignorance is the root of suffering?”
can one assert “ignorance is NOT the root of suffering?”
Both of these statements feel wrong and misleading and I cannot explain well why I should feel this way.
(from Buddhist Stack Exchange)