They are trying to cure symptoms of underlying diseases, and even that, only in ways that will require lifetime intake of drugs and followup tests.
To say that a cure doesn't exist because they are not trying for it is 1) wrong, 2) hugely dismissive of the life's effort of tens of thousands of people, and 3) dismissive of the struggle of those using antidepressants.
If you think there are cures out there that are easily achievable, show it. Otherwise you are just perpetuating facile misunderstandings of a difficult situation.
Yes, if you read Hacker News you probably object. Not everyone does that. But making the problem just go away is the prevailing, widely spread, most commonly used mode of working.