That only helps for a relative small range of N. Chess happens to sort of fit into this space. Go is way out, even a sqrt(N) is still in the "galaxy-sized computer" range. So again, there are few problems for which Grover's algorithms really takes us from practically uncomputable to computable.

Even for chess, 2^76 operations is still waaaaay more time than anyone will ever wait for a computation to finish, even if we assumed quantum computers could reach the OPS of today's best classical computers.