Why. We used to have much higher tax rates on the super wealthy. That was when America was doing stuff rather than floundering.
I'd even argue it's in their own interest to have higher taxes. There is no guarantee the current structure of society will continue indefinitely. Without a more reasonable distribution of wealth, we may end up repeating the "let them eat cake" episode.
Because there literally aren't enough of these ultra-wealthy people for them to have enough total wealth to confiscate to solve the problem.
There are any number of mathematical analyses of this out there.
Such that one person doesn't have the power to buy, legally, a presidential election, multiple regional elections, or half the politicians via lobbying/corruption.
The problem you are describing is revoking Citizen's United. What your trying to do is a patch job to another problem which is going to cause all sorts of unintended consequences.
First principles people, not these lazy slap dash approaches.
It's not about Citizen's United, because it's very specific to the US, while it's a global problem that rich people have too much influence.
Forget about elections and politicians, they can fund media empires at a loss to push their ideologies. No one should have that much power. They can buy lawyers effectively putting them out of the reach of the law. So many problems would be solved or reduced in intensity by taxing them.
People with no/little wealth will be taxed nothing/very little and the wealthiest will be taxed a lot; offer government subsidies for those with no or little wealth to make their daily spending easier, perhaps even a small UBI. All of a sudden, wealth inequality is going the other way. That seems kind of obvious, frankly.