Look around you. Are there things to be done? Parks to be cleaned? Old houses to be renovated? Run down areas of town? Are there any hungry children in nearby schools? If you answered yes to any of those, then there is work to be done.

Why, if there is work to be done, is it not getting done? What type of society undervalues such critical work such that you would look at the state of the work and think that there is not enough work for everyone to contribute.

There are plenty of jobs, there is infinite work, but the current value system doesn't incentivise this work that would improve everyone's life.

So two questions.

1. Why doesn't the current system value this work?
2. What would the world look like of that type of work was valued?

That in mind, given that you assume mass unemployment, which is questionable at best, reconsider why that would be. Who, or what, would be the cause?