That logic can be applied to every profession. But, here's the kicker and what I tell my kids:
The only limitations you have in life are the ones that you set for yourselves; never allow anyone to tell you what you are incapable of (the inference being that most people of either scared or full of shit or both).
We do not set false limitations for our kids, and I am encouraging my oldest to avoid the concept of specialization (work harder at the things you lack proficiency in) to find balance and be adaptable. The idea being that there will always be someone smarter, or faster, or stronger than you; but there will be very few people who are as smart and as fast and as strong as you. I grew up in a blue-collar family doing blue-collar things, was the first (and only) of my immediate family to become a University grad, became an infrastructure project manager by 28 and an infrastructure project director with a half billion dollar portfolio by 33, went from Lieutenant to Major in 5 years, and became the the ionizing and non-ionizing radiation safety officer (among overseeing a litany of other national programs) for the Canadian Army by 35... and to think I joined the Infantry as a Private at 25 just because. While I may not be a doctor (which is kind of a weak flex given the number of doctors in the world) I do have a very diverse set of professional and practical skill sets (art, science, mechanics, and the profession at arms) because I worked hard at achieving them... and I have yet to find something I could not accomplish by setting my mind to it.
I fully agree that I cannot do it all... as time is my only real limitation. Wouldn't you like to be capable of more?