Chris Dixon and Ben Horowitz on why a16z Crypto is now a16z Frontier, a fund for the "outer planet" founders building things that don't fit into any existing category: "Years ago, [crypto] was sort of its own world with its own companies and its own investors. The lines have blurred, and it's become kind of more part of the tech landscape." "What we found with our vertical strategy is that there's still new things that fall outside of the verticals... And so by doing this, we will have the…