I haven’t had the time to read through all the comments.
However, I don’t understand some of what you wrote.
1. What about mitochondrial Eve? I thought that her existence was established.
2. Even though they might not have been the first couple, there clearly had to be a first female ancestor to all of us, and likewise a common male ancestor.
Is the argument that the common male and female ancestor would not count as human and that amongst their offspring, they interbred to produce current homo-sapiens?