When you hear about carriers talking about their 5G nationwide it's the low band 5G that they're talking about. The mmwave 5G that is supposed to give low latency and super fast downloads is very short range and doesn't go through walls very well. If you work downtown in a major city that would be helpful when you're walking down the sidewalk i guess. I know some sports stadiums have it so if you want to watch videos while you're at the game it's good. The biggest problem is it's a battery killer so this could be the reason it's only going to be on the largest iPhone. I agree that it's going to be a negative for the phones that don't have it but unless Apple can make it have all day battery life I don't see it happening. A dead battery means 0G lol