That's assuming the alternative thing actually benefits from the money. You mention education, but we've already seen that education spending has a threshold past which spending more money no longer improves outcomes (it just inflates prices), and we're already above that level of education spending.

And even if we weren't, it doesn't follow that moving resources from one place to the other is the right choice. When you have two things that both produce benefits exceeding their costs, you're better off to do both of them.