I mean, you’ll find people using PEDs in any sport, despite the risk of bans and everything. Steroid use is also rampant among bodybuilders.
There is an “obvious market”, but why do such sport leagues or federations that openly allow those drugs exist?
I can imagine that such a thing existing would create an immediate and widespread health problem with lots of people, athletes or not, using those performance enhancers and accidentally fucking themselves. But what else could be a problem?
Just because it hasn’t been said yet, this already exists in bodybuilding. The professional league, the IFBB, which hosts the Mr. Olympia competition, does not prohibit drugs and they are de facto required. Essentially every IFBB bodybuilder uses steroids, and it’s a very open secret.
Something that does need to be considered here is that not all sports necessarily benefit from steroids, at least not nearly as much as bodybuilding. More muscle isn’t necessarily always a good thing if it makes you heavier or less mobile, so there’s already some limited regulatory effect from that as well.
PEDS aren’t limited to bulking up via steroids. A lot of PEDS use is about shortening recovery time. As an example, cycling is the kind of sport you’re describing where increased bulk is a disadvantage and doping in the sport has been absolutely endemic for years. It’s what the Lance Armstrong controversy was about and Armstrong was more representative of the norm at high levels than not.
I remember reading about Armstrong before he admitted to that, and he mentioned that he trains so that he has peak performance during the Tour de France. Then after the doping thing, I realized that’s what he was talking about.