I think experience is greatly overrated. The main reason is that languages and libraries and frameworks change so quickly in software development. How much does 10 years of experience in C++ development help in JavaScript development? It's difficult to say, but someone who has 2 years of JavaScript experience can easily be at the level of someone with 10 years of C++ and 1 year of JavaScript.
It's not really difficult at all to say for somebody who actually has experience: were I time constrained (within reason) I'd take the guy with 10 years of experience over the guy with 2, all other things being equal (e.g. the 2-year guy may be a specialist in a specific use/development case for JavaScript, or the time constraint might be very restrictive, to the point that the day or week the 10-year person might need to come up to speed isn't available).
Experience is not necessarily a big factor, and what qualifies as "experience" is highly dependent on context. However, the experienced person generally has just seen more than the inexperienced person. They've had a chance to deal with stuff the inexperienced person just hasn't. That counts for something; in some (most?) cases, quite a lot. It's a bit silly to dismiss experience out of hand, or to minimize the role it plays.
Also, "languages and libraries and frameworks" don't really change all that often in practice, in most places where software has been employed as a solution. That's a very "Web Dev is All Software Dev" (read: myopic) Valley-centric belief. You're referring to very narrow, niche instances where startups "pivot" frequently (or can't make up their mind, or are run by fad-chasing hipsters).
