I do indeed have a similar understanding, which is to say that your comment corroborates what I've read about early Buddhism.
My criticism is of the Buddhist's goal. I'm just contrasting Buddhism with existentialism, and pointing out that some kinds of suffering are noble. What counts as unnecessary suffering, as you put it? The Buddhist emphasis seems to me to be on foolish suffering, on the kind that arises from illusions and misunderstandings. But that doesn't apply to dismay at the scientific picture of godless nature.
Is it the case that the facts always support an attitude of contentment? Or are certain facts horrific and monstrous? That's not to suggest some are inherently negative, given the naturalistic fallacy, but just that some are bound to repulse those who are morally sensitive and who revere life.
But does the Buddhist revere life? Is the Buddhist humanistic in that sense of deeming life to be more precious than nonlife? Or is humanism itself an egoistic illusion, a vanity that misses the interconnectedness between all events in the universe?