The only counterpoint i can see is that god is (honestly, at best WAS) infallible.
So god made 2 perfect humans who cannot inbreed as there are no defective genes.
At some point down the line, mutations came in and introduced possible genes that could combine/dominate to produce inbreeding.
If we are accepting the premise of 2 original humans, why not 2 perfect original humans.
If God made eve from adams rib, why not have them be genetically perfect.
But Im sure there is some science i am missing where a huge genome analysis has shown that “perfect” genes have never or could not ever exist.
And, tbh, this might as well be all science fiction based on a bunch of made up stories.