Government is a single entity guided by taxpayer dollars rather than incentive to further itself. Taxpayer dollars will only be decreased by the economy doing badly. The government has little incentive to push endlessly to innovate more. When there is competition with another government, it will fund and push nasa forward, but when there isn't, it won't. Companies, when prevented from forming monopolies through either government intervention breaking up large companies or lack of government intervention stopping them from forming, will more consistently have more competition and reason to push forward. Government is good as a tool to push for a goal when you don't want the search for profit getting in the way. Funding otherwise unprofitable research, healthcare for the poor, etc. It is not good as a tool to replace systems that can work fine while chasing a profit.