I'm just back from a vacation, on which I rented a car that did not have a remote-control key. Only the driver's door could be opened by a key. From there, I could lock and unlock all the doors by pressing buttons on the inside of the driver's door.
This arrangement struck me as really dumb. In part, I had to get used to it. Our old car was entirely manual, but it had key locks on all four doors. Our new car has a remote control key to unlock any door. But the real problem with this rental car is a matter of chivalry: it's impossible to unlock and open the passenger door first, which is often exactly what one wants to do. (Call me old-fashioned if you wish, but I'm also thinking of bitter wind and rain.)