Earlier quoted context omitted.
I see what you're saying, but let me try to explain what I see as the difference between the two situations. Curing cancer is about biology, chemistry, etc. It literally does not require any experience having cancer as you stated. Just lots of research and college education. However, if you said you were going to write an app to cure "the mental anxiety associated with having cancer," and you've never had cancer, but…
Psychologists help cure anxiety, depression, addiction, etc. all the time without actually suffering from it themselves. They're "privileged" not to suffer from it themselves or even necessarily have any friends or family who suffer from it. They just do good user research before creating a solution presumably. Also, conversely, plenty of people who have "lived experience" of how they cured their anxiety with a cult…
There are multiple ways out of privileged obliviousness. One is lived experience. Another is taking the time to develop a structured and empathetic understanding.