Many, perhaps most competitions do in fact waste resources - it's only under rather strict conditions that they can lead to globally-optimal outcomes, and the competitions we see in schools and sports do not satisfy these conditions. You can in fact view the banning of performance-enhancing drugs in the Olympics as a gentleman's agreement among Olympian runners that they're not going to "run too fast".
do in fact waste resources
Compared to what?
By that logic capitalism with its constant competition is highly wasteful. Surely a system where a wise man (or a wise Latina) just tells you what to do is going to work better... right?
the banning of performance-enhancing drugs
No, I don't think so, because by the same argument you can ban any training. It's not a gentlemen's agreement, anyway, it's a rule imposed from above by governing bodies which are mostly interested in selling the performance for money.