Lol, megaprojects. America and UAE does it.
Australia and Germany are more efficient than other countries. They have a relatively high unemployment rate, but it looks like they're happy, because families have enough wealth - not everyone has to work to be happy, as opposed to less efficient countries.
Reaching that level of efficiency is going to be where a lot of the workforce goes. Back then, you needed like an ox and a few people to get some food. These days, you just need a tractor and a person. But how do you get the tractor? You need a metal industry and petrol industry.
Metal industry - a bunch of hardworking miners, chemical engineers, mining engineers, sales team, management.
Petrol industry - hardworking laborers, chemical engineers, geologists, drilling engineers, sales, management, PR, etc, etc.
Also a transport industry, construction industry, telecommunications....
So, just to get that one tractor, you're opening up a hell lot more jobs. Getting robots that create robots just doesn't happen... you need the people who can make the creationist robots in the first place. And when you have an overflow of skilled workers, the education industry booms. Enough higher education, and you'll get skilled workers teaching primary schools, which is not at all a bad thing.
Hell, if you still have an overflow of idle labor and too much efficiency, you get too much wealth. And what do we do with excess wealth? We build megaprojects, or a massive military. After all, when you have a lot of physicists, it's not too hard to build nukes.