> Some rich soon-to-be-dead billionaire tech nerds want to be able to do something every year without worrying about a judge taking that away from them.
You can do things like this, but the law either already covers this, or will adjust. If you gain money, you're expected to pay the usual tax on that gain. First few may get away with it, but once it becomes popular, audits will start.
> Individual will is what cryptocurrencies are about.
Same as above - inheritance tax.
Essentially it's this xkcd situation: https://xkcd.com/1494/ Just with wealth gain and tax office instead.