This essay points out valid weaknesses in the lean startup approach, but really loses it's edge when it suggests that "social proofs" - such as the ability to hire highly paid talent and/or acquire funding - are better, higher priority signals of validation. Yes, customer interviews too early on a "guess" that is barely thought through is not an efficient use of resources. But trying to hire and raise is a worse alternatives.

what would be better validation signals?

The Lean Startup was never written to help startups, it was written to bolster Eric Ries's enterprise consulting.

VC is a terrible model to fund basic research. "The science might work, and then we might be able to make it into something useful, and then we might be able to get paid for that value": most companies that try this spend all their time on A and then if they get super-lucky they get acquired instead of dying.

VC isn't the solution to America's short-sighted refusal to invest in science and academia.

Interesting but reality isn't that deliberate, reasoned, or scientific....

Can you be more specific? I'm trying to better understand this approach.