To me all this really says is that
1. It's limited by Millar's knowledge, and should be considered his opinion. Yes, he has an educated inside opinion, but it's an opinion, none the less. Not based on any direct factual anything. Considering how outspoken he is, those not only doping or facilitating it, but upholding the omerta are not going to hang with the guy, or give him info contrary to his opinion.
2. Doping has probably been driven farther underground and into covert workings than at any point in his lifetime.
3. Doping is likely practiced most extensively by those with the greatest financial resources, way out of sight of those like Millar.
4. We would have stopped hearing about doping scandals, which haven't really gone away, have they?
5. The power numbers are still as high as any other time in cycling history, including during recent years when riders were admittedly heavily doped.
Also, considering how effective O2 carriers are, if there were that many people clean, there would be a much larger backlash by the riders from being cheated. Not only against dopers, but in an effort to go beyond the norm to prove to a very skeptical population that their sport is clean. Instead, the opposite still prevails. Someone like Damiano Cunego speaks out in vague terms and not only does no one stand behind him, we have other leaders in the sport telling him to his face they'll crush him.
So, sorry David. I do agree it's cleaner than in the past, certainly compared to 200-2004, since which probably 2/3 of the PT has since been busted or connected to a scandal. But I think it's simply factually incorrect to imply that the sport is almost clean.