My argument would be that by eliminating the means of wealth being an avenue to power, it will merely shift to the government that is enforcing those rules. Those same shitty people will infiltrate that government and use it to inflate themselves while oppressing others. There was no utopian society prior to capitalism and fiat currency, and there won’t be one after.
To be clear, I’m not arguing that this is an impossible problem to solve. I just do not think eliminating the notion of a billionaire is the cure for all of your listed ills. I agree with you that it would absolutely have impacts on all of them, but we would still wake up to world hunger, climate change, etc.
Each of your listed issues is a complex, multi-faceted problem. We cannot boil down that nuance just so we can point to our favorite enemy, deserving as they might be. Fight them too, but don’t lose sight of the bigger picture.