I don't disagree, but the flip side would be a high level athlete who suffers, for example, an injury. They can continue competing at the same level only with m

I don't disagree, but the flip side would be a high level athlete who suffers, for example, an injury. They can continue competing at the same level only with medication. For me, this is analogous to someone with ADHD taking medication to perform closer to their level without ADHD (impossible to prove, per your point), but I would prefer to give them the opportunity rather than broadly disqualify such people from competing.