Trying to be self-sufficient is a great way to end up dying young of a common easily curable infection, or of starvation.

I don't think somebody aiming to be self-sufficient as possible would forego going to the doctor or avoid using medicine unless they were sure that their condition was manageable within their skill level.

Does this invalidate somebody's efforts to become as self-sufficient as possible? Not at all from my perspective. It's still an admirable practice and lifestyle, especially if they share the fruits of their labor or the knowledge and their skills gained with others - which is a common among those who practice self-sufficiency.