If I were an actual billionaire -- say, my net worth was $2B -- then my one-time tax under California’s proposal would be $100M, leaving me with a net worth of $1.9B. Under that 5% risk-free rate of return, I would recover that amount of money within one year even if my income were $0, which seems exceedingly unlikely.
One can argue about the specifics of various proposals -- the Tax Foundation, for example, thinks California’s proposal has “aggressive design choices and possible drafting errors” that could lead to somewhat bonkers results, although I haven’t seen any critiques of their analysis yet -- but a wealth tax cannot be converted to income tax in a reasonable manner any more than a VAT could be converted to property tax. They’re both taxes, but they’re simply not the same kind of tax. And while I don’t mean to cap on Paul here, there’s a distinct “woe, pity the poor billionaires who will surely be driven to bankruptcy” subtext I find to be risible nonsense.