There will always be a need for human labor because human needs are insatiable. Once all needs seem to be fulfilled, new needs will arise: immortality, eternal happiness, travelling to the space, travelling to the future
These projects cannot be fulfilled in capitalist economy because don't guarantee success (ROI) within reasonable timespan. Capital owners don't even invest into nuclear fusion which is soon-achievable, so why should they invest into immortality or relativistic speed travel which may be possible only after 1000 years!?
The process towards near-immortality requires little steps that can be accomplished in a capitalist (free) society. In fact, life expectancy has been increasing thanks to research and the promise of ROI on development of medical technology.
There are also private companies with the intention of exploring Mars, and lots of people willing to go there and be pioneers in a new land. Travelling out of the Solar System is again a step by step process, which may work in a free society. Why can't you go to Jupiter or Saturn after Mars has been colonized?
Some may find relief, some even happiness, in the latest anxiolytics and lab drugs. However, a less technical way of life: yoga, reading, theater, sports, helping others... may be valid answers towards happiness for many people.