This doesn't make sense? By definition, as long as there are more prospective renters than actual housing units available, prospective renters will compete wit

This doesn't make sense? By definition, as long as there are more prospective renters than actual housing units available, prospective renters will compete with each other spontaneously by bidding up their offers. That's true everywhere. That's just how competition and having multiple people submitting multiple offers work... the best offer is accepted.