tl;dr: rojo—please pull your heat out of your butt. What kind of mental gymnastics are you doing so that you don't have to confront just how widespread cheating is in this sport?
I am in the camp that thinks that cheating is not a moral failure, but an ethical one. I believe virtually every elite runner cheats in some fashion or another, and that it is extremely naive to think otherwise. Statistical arguments based on performance distributions between known dopers and the (elite) population at large show that the distributions of times are the same in both groups. In simple terms, doping works for the population at large, and it clearly shifts times downwards. There's a reason why we have the term "EPO-era." You can see when steroids became part of the sport in to 50s as well as EPO and other drugss appeared. Just look a the Arturo Barrios-Yobes Ondieki-Geb progression and tell me there's not a line to be drawn there.
Personally, I would not cheat, as it would tend to nullify any accomplishment I might gain from running. However, a lot of people don't feel this way, and we live in a narcissistic society that values 'chasing clout.'
In my modest running career, I've known people to dope, especially in the early days of the internet. It was mostly stimulants and androgens, but I actually know people who did it.
I knew a guy who faked a disability so that he could train more.
When I did cycling, I saw countless examples of cheating. There's little to no enforcement in a rolling pack within a crit, and you can *almost* get away with murder there. I saw hand-checking, slings, dangerous obstruction, and outright malfeasance.
What I've found in life is that if you'll cross one ethical boundary, you'll easily cross more, and it is only stigma and the potential for being shunned that will halt your descent.
I think many people have a hard time believing that cheating is so widespread because it makes them confront cheating within themselves, and they desperately want exemplars to look up to.
The truth is, that just because someone runs 3:27 and smiles/doesn't doesn't make them good/bad or more/less moral than you are.