OK, I hope my question doesn’t get misunderstood, I can see how that could happen.
Just a product of overthinking.
Idea is that we can live fairly easily even with some diseases/disorders which could be-life threatening. Many of these are hereditary.
Since modern medicine increases our survival capabilities, the “weaker” individuals can also survive and have offsprings that could potentially inherit these weaknesses, and as this continues it could perhaps leave nearly all people suffering from such conditions further into future.
Does that sound like a realistic scenario? (Assuming we don’t destroy ourselves along with the environment first…)
I expect gene editing soon to become so cheap that everyone starts customising their children, resulting in a situation analogous to where dogs are now: extreme variability improving the chances for survival by making sure we have the needed people for any situation except gamma ray burst which requires backups far from Earth.
I’ve been working on a sci Fi show where humans have this but they also have the ability to change their current physiology by infecting themselves with modified strains of cancer that slowly replaces you’re body with one you downloaded off the Internet this technology has also sorta obsoleted medicine because if you have a broken leg or infected with a fatel desese so long as the injury doesn’t affect your brain you can just replace your entire body by infecting yourself with genetically modified cancer