As a producer of Toronto’s NYE fireworks for many years, I can tell you why the kit still matters. When a few hundred thousand people hit the same cell towers at once, the network folds. Phones drop frames, lose the feed, or go dark right when you need the shot. Professional crews use bonded cellular, dedicated microwave, or satellite so the broadcast stays up when the public network doesn’t. The flag is usually required by the record rules or the official coverage, not decoration. Good on him for doing it the hard way.