There is simply no use for one individual to have that much wealth. Tax it, and individuals will find creative ways to put it to use instead of hoarding it.
You seem to think the ultra rich have Scrooge McDuck style swimming pools of cash or stacks of gold bars in a cave somewhere doing nothing but somehow "storing" accumulated wealth.
This is generally not true. Most billionaires appear to have most of their wealth in the form of stocks in a company they run. (AKA investment in the economy)
There's lots of valid criticisms to be made of extreme wealth inequality. The rich supposedly "doing nothing" with their money doesn't seem to be one of them.
That's a lot worse. Owning stocks means having control over a company and thus power. One unelected person having so much more power than others is incompatible with democracy.
A Scrooge McDuck style gold pile, in contrast, would make gold slightly more expensive but wouldn't influence the economy otherwise.
Wealthy musicians are still capitalists, and getting rich running a business that employs thousands should be as respectable as singing, if not more so.
I think the view that Schulz shouldn't have more than 500 million isn't unreasonable, but it seems very clear to me that he should have more than Beyonce.
That Beyonce is the most talented and hardworking person? That no one should have a higher net worth than her? You have some very strange views.