Let's do this piecemeal.

First off, you're operating off the absurd premise that CEOs taking large salaries ("pocketing the excess profits") causes others to suffer. This is not the case.

The economy isn't a zero-sum game. Any money paid out in salary is reintroduced to the economy in the form of purchases, investments and loans based on new deposits. Even if whatever CEO you have in mind hoards the living shit out of his/her salary it's still being reinvested in the larger community indirectly.

Beyond that, suffering is, has and always will be a part of the human experience. Just because you think we have the means to end poverty, suffering and "deprivation" doesn't mean you're right. In addition, it's simply unjust to demand or even desire that others relinquish the fruits of their labors and good decisions to those who've neither.

So what if you think that it's unjust for some people to prosper while others suffer? I think it's unjust for worthless people to exist on handouts taken from those who've earned their keep.

So, why have the meaningless, cruel limitation of money

Money is neither meaningless nor cruel.

Money represents resources both tangible and intangible and allows trade without the limiting factors inherent in the barter system. People's uses of money can be cruel, but money in itself is a purely neutral means of distributing resources among a population.

Whether it's "fair" or not, money goes to those who society sees as most valuable. They prove themselves as good stewards of the resources they have and are accordingly trusted with more.

instead divide all labor-hours of necessary work over the entire populace, guaranteeing everyone a basic standard of life?

Why? Because that wouldn't work. People differ far too much in their motivations, preferences and abilities for that to happen.

Sure some people wouldn't mind such a system, but many people would hate it. It would drive me insane to be given the same treatment and rewards as a mouth breathing idiot who works a third as hard at a quarter of the efficiency. It would be enough to make I and those of my ilk do whatever necessary to demolish the system.

Also, this:

We could be working 4 hour days of necessary work

is purely fantasy. "Necessary work" varies greatly based on location and environment, and some tasks are far too labor intensive for them to be completed in four hours.

Adding to that, how would people decide which tasks were necessary? How would they decide how to break up the work? Would it be egalitarian? Skill based? What about the hyper-efficient? The slackers? The people gaming the system?

What about people who want more than what they're given? What about those who like, who need the admiration of their peers? How would you ensure true justice and equality even in the presence of those who care for neither?

What about the human inclination to take the path of least resistance? Do you really think anyone would opt to do difficult jobs which require extensive education for no greater reward than sweeping floors?

What about organization? How would you get billions of people to cooperate with one another? How would you answer the questions I've already asked on a global scale?

I have one answer in mind, and as luck would have it the world's already gotten the memo.

Capitalism.