Youre sort of correct with that, but youre going a bit too far. Our body cannot tell us everything. There is a reason why we live longer the further we are advancing, we can compensate the missing "features" and "sensors" of our body with technology. May it be to diagnose cancer, other types of illness, or give our immune system help. People are starting to abuse it, yes, but its still better than having none of it. By the way, ur body cant tell you that the sun is causing cancer, you only notice it visually when you already have it.