This feels like an ivory tower take. I worked at a job reentry program. The difference in outcomes between those working hard and those not looked pretty stark to me. Ignore the billionaires. Focus on what you can control.
It seems that you are paid for how many lives you affect (and to a lesser degree - by how much you affect them), rather than how much work you do.
This is brilliant observation!
This is a good point. If you think about it everyone is successful for a given low enough threshold for success.
Getting a different, better, job can make a bigger difference. If you can both find one and qualify for it.
I'll answer for me it's a situation where more effort translates to more progress.
Whether it's progress toward success or away from failure, and whether the success or failure are financial or not.
So I like to work to build a situation like that so that further effort pays off the most.