if there was a cure for every diseases than a lot of Prophets and Sahabas would not have succumbed to simple diseases like Fever, Leprosy etc. etc. Please do not defame religion by making false claims. It is natural to die and Islam never claimed that there is cure for every disease,
I have already phrased it but in a different way. The bottom line was that not necessarily all human efforts lead to a cure. Example millions still die to Cancer, flue and Malaria. Even with the most advanced scientific tool we can only do so much. There is a limit to growth both economic and intellectual. Human intelligence although remarkable compared to other animals still has its limits.