>>Nobody is advocating the killing of any offspring. The unused embryos can be stored perpetually, if one desires.<<
LOLOLOL!!!!
Or not.
I think a lot of people have the misunderstanding that fertility clinics destroy unused embryos, or that fertility clinics decide to donate them to science.
These decisions rest with the parents of the embryos.
Clinics are terrified to destroy embryos, even those whose parents have long ceased paying the storage fees.
So clinics—many of which don’t want to be in the frozen embryo storage business to the extent that they are—are faced with a growing problem of unclaimed frozen embryos, and more are going to collection agencies to try to get the storage fees paid from the parents who have vanished.