As a 22 year old dev, "valuable" can be defined as writing code and building products while working 60+ hrs a week, which is what many do in SV. As you age, you write less code and contribute to building products in different ways like architecting the platform and thinking about the business more than the product itself. This is what experience gets you as you age.
I think you're saying that the later deserves more compensation and no 22 year old is worth $200k. I don't think that's true. And most of SV doesn't think that's true. SV likes people that can build and make things, and will pay someone handsomely to build a product and iterate.
My team of a designer, product manager and two software engineers built this. We created millions of dollars in new revenue for our company.
Prior to this another off-shore team had tried to integrate something similar from our partner's competitor. They failed to complete the integration.
This is why good software engineers are paid so much.
Surely the problem is that those companies are earning absurd amounts of money while contributing very little to society. They've got billions stashed offshore that they literally don't know where to invest. Even after paying this much to grads.