Would depend how it’s achieved. The most realistic way would be through mass automation, but the question is now “who owns the machines that produce everything?” A minority controlling these means of production would mean the rest of the world is at their mercy. If they manage to maintain their ownership (though a fully automated defense force, I guess), they can have the rest of the world doing whatever they want… But what do they need these people for then? All they are is a threat, as they are prone to revolt. Genocide seems like a handy option if the elites are sufficiently ruthless, but it would be hard to put in place; there are many people in the world and they can be inventive when fighting for their lives. Beside, there would probably be several such elite groups, still divided in different country; one who starts building large armies and stacking weapons might attract hostility from their neighbors. Providing the people with their needs to pacify them? Sure, but what if they want more? Or what if they make their own automated armies with the free time they have not worrying about starvation? Keeping them occupied seems safer. Why not invent some bogus job that doesn’t actually need to be done and have them believe they still need to earn their living? That could solve the problem from the elite’s point of view. So basically, no change for the people.

With collective ownership of the means of production and an egalitarian spread of wealth, it could be cool tho. People would just do whatever they want, many would still probably undertake collective project, either to further better life of for the fun of it. There could still be forms of conflicts about how some things are managed and by whom, tho…