Steroids don't make up for anything, almost all pro athletes use performance enhancing drugs(PEDs) and evade current testing protocols. The testing just prevents athletes from going crazy and taking a ton of drugs. This is very important for the long term health of athletes, going completely open on a drug policy would be disastrous, right now it's basically an arms race between WADA and the athletes. The athletes that are the best currently, are the best because of genetic advantages+taking PEDS. PEDs do not equalise the field when almost all athletes are on them. It's not a moralistic argument, it's just how it is. Genetics will always play a massive role in top level sports. There is no way around that. If everyone is doping and evading drug tests, the genetic component becomes the main differential. For instance, all of Usain Bolt's competition has failed drug tests. Bolt still won most races, and I don't think he was completely clean either.

And that's not even getting into athletes genetic response to PEDs. Some people are hyper responders to certain drugs and steroids just because of their genetics, while others barely respond. Bodybuilding is a sport where you see this a ton. Some people just blow up after taking certain substances. Again, all because of genetics. Sports competivenes is always going to be highly dependent on genetics, even if we allow athletes to use whatever drugs they want. Then the genetic response to PEDs just becomes a bigger factor than it was before. Those that can genetically handle being juiced to the gills without dying will just win everything.