There's a big Russian doping scandal presently breaking. It appears systematic, obligatory, with conspirators as high as the IAAF itself. It does not appear surprising, however. At least, not to me. Not to people who... I don't know.... watch sports at all? Any sport will do, really.
Still, I don't expect the broader reaction to be that cynical. We're very comfortable seeing Russians as "the bad guys", a nation of Ivan Drago science experiments turned athletes. Putin's last few years have done nothing but solidify that enmity.
Even among the running community, I imagine much of the reaction will be that, well, it's just them. Or mostly them, Turkey, Morocco, and a few other nations that make up the bulk of positive tests. The reality, I think, almost must be quite different, given that many athletes compete with and/or defeat these now known dopers. There certainly isn't dominance approaching a Ma's army level.
Given that, we can only assume that A) The talent gap is just that big; B) Doping is more or less a global precondition to success in high level athletics; C) They're micro dosing to avoid suspicious results; D) Something like all of those, mixed together, and some other stuff that hasn't occurred to me.
Still, at least we can be assured that - Comrades aside - ultrarunning is surely a pristine sport, filled exclusively with nice people who would never cheat. Just like how we know there's no doping in high level soccer. We're so sure of this that there really isn't even any testing. How much more proof could you ask for than the winking compliance of FIFA?