The idea that because "everyone" (it's never everyone but whatever) takes drugs, then it's a level play field is flawed.
First I'll give cycling example, because that's something I understand better. Some cheaters used to say that it was a "level play field" because everyone took EPO, but the thing is... those with a higher natural hematocrit count, lost their natural advantage due to better genetics that those with a lower count. Also, when the 50% limit was enforced, those with a higher natural level could only cheat 2-3% but other could use EPO to gain 5-8%. Not fair, not even. And there's also the money problem: some can pay for better drugs and better ways to mask them, some can't, and that's a huge difference.
I don't now much about strength sports, but I guess that people with lower natural testosterone would gain more from cheating than others, for example.