It's not strictly necessary but it takes giving a crap and effort and constant auditing and reassessing to do all that light timing well with the current state

It's not strictly necessary but it takes giving a crap and effort and constant auditing and reassessing to do all that light timing well with the current state of technology. Outsourcing that responsibility to centralized computer that can do most of it automatically and on a schedule is likely a huge improvement for the quality of programming/timing for the average light if only a neutral for the best ones.