> Taxing non-liquid wealth… I would rather address the "Buy, Borrow, Die" paradigm… like restricting the classes of assets one can borrow money against to force liquidation
The point is that to justify the concentration of capital, the company should be doing well enough to tank the tax. If they can borrow money against the equity then that gives them liquidity, and they can use it to pay a wealth tax; and if they can't repay the loan (presumably because their equity didn't appreciate to a point where they could re-negotiate the loan terms) then there's your forced liquidity.
The point is that to justify the concentration of capital, the company should be doing well enough to tank the tax. If they can borrow money against the equity then that gives them liquidity, and they can use it to pay a wealth tax; and if they can't repay the loan (presumably because their equity didn't appreciate to a point where they could re-negotiate the loan terms) then there's your forced liquidity.