To be serious, I think that this illustrates that high-tech (or 'new-fangled') equipment is by no means the be-all-and-end all. It sounds that what you have seen is that a knowledgeable, intelligent and sensible electrician can more often than not diagnose faults using only very simple equipment, together with their brain! It's the ones with only simple equipment and "no brain" that you need to be worried about!
Kind Regards, John
