> The real use of money is to buy freedom
The real problem is: This additional freedom you can buy with money means less freedom for somebody else.
Inequality (wealth-based) means nothing else than domination. If you are richer, then you dominate the poorer people. And richer countries dominate poorer countries.
This is the most basic and fundamental injustice [0] we seem to accept in our Western culture. Because we are those who dominate.
[0] If you remember that we keep telling ourselves the nice little story how every life has the exact same value.