Is a Muslim sinful if he neglects and disregards the annual comprehensive medical examination, and is consequently afflicted by harm, acting against the well-known saying: "Prevention is better than cure"?

It is permissible to undergo a medical examination, whether annual or monthly, but it is not obligatory in Islamic Sharia. Allah Almighty and His Messenger, peace and blessings be upon him, did not obligate it, nor did any of the Islamic jurists state its obligation. If treatment itself is disputed regarding its obligation, then how can it be obligatory for a healthy person?