Sounds too good to be true.
Let's not muddy the waters by talking about the global doping industry, or non-aerobic sports like bodybuilding, or steroid benefits for women.
If blood doping is so powerful and methods so sophisticated, and results virtually guaranteed, how is does it make any sense that John Walker's 2000 performance from 1976 is still relevant, all time? If we look across the board, in the more frequently run, from 800m to the marathon, how does it make any sense that American, European, Asian, and Oceanian men failed to make any impact on the sport while East Africans and North Africans routinely could, relative to performances from the heyday of the '70s and '80s? Especially in the '90s, before WADA, and before blood doping detection existed. If it were as simple as taking EPO at altitude to get double the benefits, surely many non-African athletes from wealthy countries with the means to hide doping would have replicated what Lance and other cyclists did for decades, hiding and training in the mountains.
Surely the big business doping industry did not target just poor rural nations in East Africa, and small countries like Morocco, while ignoring all of the rich countries, where the demand for doping must have greatly increased in the '90s, during the rise of the African-era.
Since the historical performances are etched in stone, arguing widespread prevalence, and guaranteed effect effectively contradict each other.