When things do not work with someone, it can feel that "had I done X, i might have worked"
But the failure helps you to avoid getting in love with this person which you are likely incompatible with. Sometimes, obviously it will be an accidental problem in the date. But many times, the failed date is a good selection system to avoid exactly those people that are not that compatible.
A study shows that many students become less interested in academic careers throughout their PhD years.
It sounds depressing "this arduous system is de-motivating students from becoming academics".
Reading the study above, however, it becomes clear that students' preferences get crystalized over the arduous process.
Maybe academia is better off when it only keeps the people really in love with reading papers and publishing them. Assuming those are somewhat good proxies for useful scholars.....