Or am I misunderstanding the cap?
For example, some sales people at tech companies make much more money than mid-level managers taking home a couple hundred thousand dollars per year. Some of those sales people will make more than the senior level executives. Which one is more important and is higher rank is up for debate.
In my comment above I tried to explain a way to fix the loophole that byrneseyeview listed. Saying nobody makes more than $500k is a way to fix that.
I find the aversion to fractional reserve banking that is frequently displayed on the internet quite odd.
This is true, but fractional reserve banking is inherently unstable: bank runs happen, and will happen (eventually) to any bank without government guarantees.