And
> We would be in a world where only work is done that is needed
Contradict each other. Of course no one WANTS to work but there are things that HAVE to be done. Like farming, hunting, building shelter. Chopping firewood to keep warm in the winter. You know, modern, made up problems like that.
> We would live in a world where everybody has the time and freedom to pursue their own dreams, without having to be afraid they will get in trouble later (because no pension built up etc).
There is very little time to pursue anything other than survival in a subsistence existence. And you better hope you have children to take care of you when you're physically unable to complete the work.
The fact that people have any time at all to dedicate to non-survival-related pursuits should tell you how important all that work that we're not "meant" to do is in the broader scheme of things.