Well...mankind is mankind and always has been. It's the availability of cheating methods that is problematic and I don't see a reversal.
If you buy-in to the romance and purity of sport then these are hard times. There will never, ever, be a return to any sort of purity-slash-level playing field due to the human tendencies that you referenced. We know that most successful endurance athletes cheat. We simply know that now because those that get caught/busted clearly represent just a small percentage of those who cheat. Is there any argument to the contrary?
Has Gladwell covered the "tip of the iceburg" phenomenon as applied to ethics violations yet? If not, there is fertile ground there for him.
Athletes cheat. Officials cheat. Managers cheat. Owners cheat. Etc...
One interesting question is: Does the cheating entirely ruin the enjoyment of the sport? The answer here is getting close to: "Yes"
For many fans of team sports the answer is "clearly no." They like seeing the game played out and there are factors related to strategy, coordination, etc... that distract from the otherworldly athleticism.
Anyone familiar with Russell Westbrook in the NBA? He's the basketball equivalent of a Dibaba sister, yet no one seems to care how he's doing it.