Have you played sports before? Even at the high school level teenagers are pumping their body full of steriods. I saw them do it myself, I've heard the stories from my friends who played rugby. Just look at top high school rugby or american football teams physiques, or at the cardio capacity of teenage track and field athletes. You really think that level is attainable without performance enhancing drugs, at such a widespread level? You really think that stops once these athletes become adults? How about the fact that all of Usain Bolt's competition got caught doping? You can't be this gullible. Seriously, read the article I've linked below.
Russia's sin here was official state involvement, not doping. As long as you pass the drug tests, nothing matters. Remember that Lance Armstrong never failed a drug test. Does that mean he's a clean athlete? Of course not, and neither was any of his competition. The same applies to the Olympics, the same applies to almost all competitive sports.
I'm going to assume you follow one or both, and that you're aware of the high prevalence of PEDs in both.
Now how are Olympic sports different than those leagues? Is there less of an incentive to cheat? Is the IOC more interested in preventing cheating? Do the athletes not care as much?
If anything, there is likely more doping in the Olympics because you have the resources of state actors backing athletes, see, e.g., Russia.