Froome grew up in BFE Africa... what junior races was he supposed to tear up? For a guy with little experience, he did quite well early on. There's a big difference between the progression of a guy that starts racing at 12 and grows up in a cycling country like France and a guy that starts at 17 in Kenya.
Also, Vo2 max is developed, not totally inherited. It is genetic to a degree, but people can develop it. And heres the tricky part: Some people have the genetic capacity for greater improvement over time that others.
So, what you do at 18 isn't indicative of what you do at 27. It can be, but not always.
Just some points to consider.
Also, just to be clear, his vo2 max could be 80 and he could still perform as he does, if he had great efficiency and lactate clearance. Vo2 max isn't a great indicator of much. I shouldn't use it. Sorry.
So, 6 w/kg is something to focus on more concretely. Its what is going into the road.
If vo2 was the best indicator, I should have been better than Lemond. And I wasn't. Ever. even doped.
But, honestly, I don't care. If you guys wanna think Froome dopes, go for it. have at it. I do not care..
Just trying to give you some alternative methods to think on it.