You contradict your own point. Even that adage accepts that the upper bound on the amount of experience you have is based on the time you spend. You can have 1 year's worth in 1 year, or 1 year's worth in 10. But you can't get 10 years' worth in 1 year.

I think experience is vastly overused in hiring; it's a classic example of picking the easy thing to measure over something meaningful. But experience really does matter. Living with a code base for an extended period teaches you about consequences that just aren't obvious.