I could also decide to cheat when being in the top players in the world. Even better, because I would only need to use my cheats sometimes and hide it even better because my knowledge holds up enough.
And the best player in the world could cheat, too, reducing their mental load and taking it easy.
Both cases would likely be exposed by the cheaters getting lazy.
It is possible that some people can reach quite a high level but top out in their natural abilities well below the absolute top of the game and be incentivized to cheat to break through their personal, natural ceiling.
Even worse than "some people are cheating to make it to the elite level" would be "everyone at the elite level is cheating, you can't compete without cheating".