For myself, I don't like them because I know they come with health risks and that makes me watching the events like a roman citizen watching gladiators die for their entertainment. And I try to stay away from that as much as possible.
"There is evidence that the pattern of banned substance use in elite athletes is high, yet morbidity and mortality of elite athletes is not greater than the general population, and former elite athletes live longer and healthier lives than age-matched controls. There is evidence that misuse of PEDs, often obtained from the black market, without medical guidance or intervention contributes to morbidity and mortality in recreational athletes, but this pattern is not evident in elite athletes."
Even in events you don’t watch, like the Bumphuck Senior Games 40+ Steeplechase, people are doping. And as a competitor in endurance sports, I don’t want to have to take PEDs and risk my health just to stay competitive in bullshit, no-one-cares-but-your-Mom local amateur events.
And if a frog had wings it wouldn’t bump its ass when it hops. You asked for the argument against PEDs, and right now the argument is that they have adverse effects on health. If the health effects ever change in the future, then we can revisit.
Fair enough. I think ketones might be a parallel to what you're thinking. Seems to be safe so far, seems like it could be beneficial, still legal. But at $5/day, I'm hoping that shit doesn't work because I don't want to have to spend $5/day to remain competitive.
Professional sports inherently come with health risks. They are unhealthy almost by definition.
If someone wants to risk their well-being for achievement, fame, big money and/or anything else (which is crazy, but people do crazy stuff) - it is more beneficial for the society if it's all transparent and goes into scientific papers and not some anti-doping agency or court papers.