There was an article in Omni magazine back in the 70’s that actually addressed this issue. The graphic accompnanying it showed a sickly looking human brain with legs and eyes, sitting in a tree and it basically made the argument that, now that we can cure the sickly to reproduce, the human race will no longer get stronger with each generation, but weaker.
It made the argument that those alive today are the progeny of those that survived previous plagues and pandemics. But if we can now protect those that would not survive on their own, our genes will continue to weaken over the millenia.
The human race is an evolutionary dead end, because we figured out how to mess with natural selection.