Perhaps you can argue that startup equity grants should be higher. Would hiring issues be resolved if the average equity grant tripled? Would more talented people in the U.S. pursue Silicon Valley careers if they got 3% instead of 1% to be an early employee?
I can't prove it, but I'd conjecture it would only have a modest effect. The notion of "expected value" of equity is problematic. It's not like it's simply a 3X stronger offer. The bigger issue is whether the company will be worth anything at all.