You two seem to think that being competitive swimmers gives you a much better perspective about ANYBODY ever needing a snorkel to swim. I would argue that the exact opposite is true, because not everyone is a strong swimmer, so your perspective doesnt account for this. For some folks a snorkel really helps their swimming.
Me for example, the hardest part of swimming for me is turning my head and breathing without gulping air. I just cant do it well. So I generally either swim with my head out of the water (which is less efficient) or on my back. But if I have a snorkel, I can swim much faster.
I still dont wear one on my mask, but I bring a foldable one. If I ever had to swim a long distance, I could do it on my back, but I would want to have one with me.