He suggested that this statement parallels the concept in Buddhism that 'all is suffering'.
I don't think so. In fact I think this understanding of contemporary Buddhism is useless and inappropriate.
Until 70 years ago nearly every disease we have ever heard of, was plaguing the human race. At birth most people faced foot, leg, facial and spinal distortions in addition to the high probability of killing their mother as they came out of the birth canal.
Before that, going back to the 1850s, most people faced a life of hunger, a life with only a few dozen potential lifetime occupations and they were entirely dependent on where they were born in the social hierarchy.
I call that a life of ‘suffering’. That was the old, irrelevant Buddhism. For us, it is gone.
What we have today is a world that is not ‘fair’. If fair means that everyone gets 100% what they want. The fact is that most people do get 85 to 95% of what they want.
People going to psychotherapists tend to be in circumstances that are often created by their own misperception of the world. Correcting that is the function of the psychotherapists. If they know what they're doing they can help reconcile the conflict between self-concept and social reality.
I think Buddhism has some intellectual contributions independent of the concept of suffering.