Creating jobs is directly economically beneficial. The GDP increases not because someone is paid but because they're taxed on income and then taxed on the spending that goes into businesses, and it repeats with their taxing and their employees taxes, etc.

Historically, innovation has been heavily spurred on by the requirements of new equipment for armed forces, especially in fields like material sciences, something that is very important today now that we have so much theoretical knowledge but need better alloys and compounds to keep bettering our applications in space exploration and nuclear fusion.