Most economic debate occurs in spherical cow land because it ignores the political realities of the debate. Sure it would be possible to have a wise, far-sighted government that invested in exactly the technologies that were needed for the future. But once the government is a source of patronage, politicians have a huge incentive to funnel off the money to their friends and cronies. In the end, it is usually better to leave the government small and accept that there is some long-term planning you'll miss out on.

In the same way, if we could have a benevolent dictator, he would certainly govern better than our crappy government. But dictatorship is inherently unstable because the most ruthless person seizes power. So the dictator could not stay benevolent for long. Better not to have the dictator, even if it means having a less efficient government.