The existence of stuff like this is why I'm always so skeptical of "fix everything" plans such as what Harris apparently recently said about taxing unrealized gains. I heard it secondhand but it appears that whopper of a tax is 'only' for those with income or assets or something over X hundred million dollars. Guess what though? The venn diagram of those folks, and people who can afford attorneys to evade such a tax by methods such as described here, is a circle. And when that scheme brings in far too little money, I assume it'll be expanded downward till it actually hits those of us who are just trying to get to retirement and may or may not make it.
Harris explicitly said only for people worth $100 million. You can have the opinion that politicians will derive from their plan, but it is a big assumption, nothing else.