Everything is eventually going to be handled by someone else. Eventually the surgery patient is going to be managed by the nursing home, but it doesn't follow from that that the surgeon is second fiddle to the rehab nurse.
Let's take a closer look at the analogy proposed, that EM docs are like "second-string quarterbacks." Does that make any sense? Do you start the game with the second string? No, you start the game with your best player, and they hand it off to the second string. That's why we call the best player the "starter." And that's what the EM doc is -- the starter.
EM docs are the best at EM, and other docs are the best at what they do, so a better football analogy is not first-string and second-string, but people playing different positions. In the ED, you call the play, and then you either pass, hand off, or scramble. Your internists and surgeons are like your running backs and wide receivers.
The "triage nurse" meme is kind of like the running back and the wide receiver sitting down after the game and saying that the quarterback really isn't excellent at anything; he doesn't run as well as the running back, he doesn't score as many touchdowns as the wide receiver. All he does, really, is pass the ball, and ANYBODY could do that (with an unlimited amount of time and no defense pressuring them, anyway.)
The quarterback reads the field and executes the play, quickly and under great pressure. He doesn't have to take the ball into the end zone himself to be successful.