If I hoard a billion news papers clippings I'm a mad man but if I hoard billions of dollars I'm a hero this seams like a bit of a paradox in itself no?
If you literally "hoard," as in store it up and hide it away [1], yes, that would be crazy. But nobody does that. Those billions are invested and working.
Come on mate you know what we mean..
I'm not even calling to get shot of billionaires, I just want them to pay their damn taxes
I know what you mean, and I agree with you. But OP was literally calling for a wealth cap [1].
Why? What benefit does society gain from telling Elon Musk, years ago, no more money, go buy cars and nice dinners, you're not allowed to start SpaceX or get involved with Tesla?
Also, it's trivially sidestepped. Japan is a culture with notoriously uncompetitive executive pay. As a result, one, its ambitious tend to not do their work there. And two, many firms have the entire family on the payroll. (Beyond that, a deep system of patronage.)
The U.S. government is more than able to spend on these things today. Spending isn't constrained by taxation. We don't do those things because we don't want to. It's magical thinking to imagine that if we expropriated wealth, that it would be spent on what you want it spent on.
Also, if only we had historical examples of governments that confiscated wealth, and how that turned out for its poor...
In any case, Elon Musk is a pretty bad example because most billionaires do not orient their investment activities around some forward-thinking idealistic goal like Elon has. For every Elon, there's a hundred very boring billionaires who are perfectly content with swinging their wealth around in ways that just make society worse, like lobbying politicians and buying up chunks of economically valuable real estate in cities.
Money is power, and power begets more power. People shouldn't be able to circumvent democracy no matter how cleverly they've played the economy game.
After a certain point - when you can afford literally everything it's possible to want to consume - it's no longer about improving your own quality of life. It's either about increasing your "score", or about increasing your power over others.
If you hoard millions of dollars, it's not really the same: it's effectively saying 'I'm going to do whatever I gotta do, in order to seize unthinkable power over everybody I interact with, and rule them'. The money isn't useful in itself past a certain point, it's keeping score and it's a marker, showing what you can do if you want. It's a lot like if you are able to make nuclear weapons and you're hoarding uranium. It's not an inherent value in the uranium, it's what you're prepared to DO with it and how people must interact with you, knowing that.
Wealth legitimizes this, and that's the problem. But civilization is a long history of society taking on these problems and slowly, awkwardly solving them only after it became impossible to continue any longer as things stood.