Then nothing changes in your fantastical scenario that I find a $1B painting in my attic and sit on it.

What we're talking about here is when people like Jeff Bezos have billions of dollars of income--direct income from gains realized in asset sales, income generated from property, stock sales, salaries, etc.--we shave a significant portion of those gains off in a wealth tax.

Well that's just another unworkable scheme. The income is already taxed at the highest rate so what you're suggesting is base the income tax rate on how much a person is worth, like if they are a billionaire make the tax rate 99%. How would the IRS determine a person's financial worth without doing a complete audit of all their assets? That could take years for a billionaire.