Yes, I was using your lack of an answer as evidence, and not your question.
You are still mixing up "knowledge" with "belief".
Does anyone of "most people" actually "know" if Bekele, Geb, Komen, El G, Kipchoge, and all the other greats I forgot, actually doped?
Everyone knows a lot of non-Africans dope too, yet compared to the 1980's, the best of the rest is less than 1% faster.
EPO doesn't really seem to be that much better than old school blood transfusions, and steroids, unless, apparently, you are a high-altitude adapted athlete.
I'm still wondering what happened in anti-doping in 2005, that had such a massive deterrent effect, about the same time that legends were retiring from the track, and new replacement talent was going straight to the roads.
Bekele still ran the 4th fastest 10K in 2008, and the 2nd fastest marathon in 2016.