You might want to re-think that. Places where people do not live are generally like that for a reason. How much fresh water is there? Do we really want to have more places on the planet under water stress? Do we want to ship water there? Is it hot as hell there? How much of a persons income is needed to survive with modern conveniences? What is the carbon cost of living there?
>We need to rethink how money is created and distributed.
That has to happen, but will it happen? For example, after the horse was replaced by the car, did we keep millions of horses around? No, there numbers dropped significantly. If technology can truly replace huge numbers of people, the people left with the capital may think that getting rid of huge portions of the population is a valid outcome. The truly scary thing is it may actually be a valid answer.
Rethinking income/money is definitely a must, but right now we're totally dependent on it...
There is still plenty of room to grow and improve. Africa and Asia have huge amounts of land that are nowhere as dense as the US, let alone Europe.
> we need something for those who will simply have nothing to do in order to make money...
We need to rethink how money is created and distributed. Once you do that, the need to "make money" might be lessened or replaced with different ones.