What Fuels Dutch Female Cyclists?

I can't help wondering how Dutch female cyclists can be so successful all the time. It's practically the case that if van Vleuten is in a race, everyone might as well go home because they can't possibly win. I don't see women from any other nation dominating race after race, year after year, the way the Dutch women do. I don't have exhaustive statistics to prove my point but it seems every time I watch a race that has Dutch women in it, I can guess who will win without much effort.