So I see nowhere where I denied the bonding aspect of marriage, however the word is "shall.'
What you have is a cultural interpretation, what scripture states is in the case of Adam and Eve, they already were one flesh, then they became two flesh (she being his rib first and then her own), then they become one flesh again via the procreation of producing their descendants who are the combined flesh of both Adam and Eve.
Believe as you will ,but this is the historical-biblical understanding of "one flesh" and it has nothing to do with married couples who cannot conceive, but it is about protecting marriage as the proper place where from children should come.
Divorce cannot undo "one flesh" because one flesh are the children.
But couples can get divorced.