While I do agree it looks unfair, the "rich" also risked the most, so it's only fair they get the most. Bigger risk = bigger reward. Bigger risk also = bigger loss.
With an equal percentage per annum (4.5%), the rich coin holder gets more coins due to the amount of his contribution. The contribution of 5,000 coins will reward 225 coins for the year. While the small holder of 100 coins will get only 4.5 coins per year.
225 coins is the reward for higher risk.
Your model is unfair. And most importantly, it will lead to the centralization of coins in the hands of large holders - because they get rich ahead of ten times faster than others.
You are talking nonsense. What else is a casino here?
You hold so much, you get so much, you hold less, you get less. What is not clear here? What does justice have to do with it?
Put 5000 in the parking lot, and you and I will see if the conditions are fair for you. I am sure that you will say that this is too high a risk.
P.S. Justice does not exist. Throw this nonsense out of your head. If you want to get justice, then do it yourself.