Empirically it's really quite rare that eating less than your caloric expenditure is going to make you unhealthy for obese people. It's a rare caveat, not ground for blanket dismissal.

Feeling hungry or being unhappy with such a diet is more common, but it's generally also fixable, and it doesn't defeat the point either.

No, I’m saying I’m making no claim on that because I very much don’t want to get into the (very) subjective and context-dependent argument about whether a diet is a good idea for someone or not. My claim is much narrower: CICO works if you follow it. Whether it’s right for you, I can’t say.

(For my part, CICO worked amazingly well for me, and I was able to follow it without much trouble. But that’s just me.)