What could entail maximum well-being, a world of wealth inequality, or a world of wealth equality?
There are a few theories about this. I'll define wealth inequality as uneven distribution of money between adults.
One thought is that if everyone was having the equal sum, then there won't be in many cases motivation to work hard, nor excel. Production rate, aswell as skill levels decline. Metaphorically, what would motivate the failing student to study when there seemingly wouldn't be any benefits for it, and why would the A+ student continue to excel, if they'll get the same as the failing student?
Furthermore, one could imagine ethical problems when the state "must" interviene to make things equal again. Due to some people for any possible reason is given extra money. Maybe gave him extra to motivate doing a better job for them, or to show gratitude or validation.
The state taking peoples property or money, and the level of survailance/lack of privacy needed in order to make wealth equality the case, could also be thought to be (unacceptably) ethically problematic.
Would there be less well-being in that type of state in the world or more well-being, than a state of wealth inequality?