You could generate a lot of revenue via a rule (enforcement TBD) that requires people to establish a reasonable valuation on an asset before they can use the as

You could generate a lot of revenue via a rule (enforcement TBD) that requires people to establish a reasonable valuation on an asset before they can use the asset as collateral for a loan. Then anyone who wanted material benefit off of their wealth would be required to pay taxes on it, rather than "benefit now, leave the gains to my estate".