It's easy to do and not very expensive (it's only the time involved to do repetitive changes in coilover height), and will make any car handle better. It's not really necessary for a street car, no, but it can only make the car perform better. This sort of hinges on the assumption that the car has enough chassis stiffness and bracing to not be a wet noodle though. The stiffer the chassis, the more you need corner balancing.

If I had adjustable coilovers, I'd have corner balanced my car already, but I have access to a few sets of networked digital corner scales so it wouldn't cost me anything.