[harshreality]

There's a strong filtering process. You're ignoring all the people, fetuses, embryos, and gametes that never pass on their genes.

When genomic damage gets too significant, and damage occurs to critical genes, individuals do not survive to reproductive age, fetuses are miscarried and aren't born, or embryonic development breaks and it might not even be known that fertilization occurred.

Aren't there also mechanisms that reduce accumulation of genetic damage in gametes compared to the rest of the body? That helps too.