The beginning of your discussion is focused on income tax and capital gains tax. Later you mention taxing unrealized paper assets, but politicians like U.S. Senator Elizabeth Warren want to tax all assets. They want a wealth tax. Interestingly, inequality of wealth is even greater than inequality of income.

[Begin Warren’s proposal]

(1) Zero additional tax on any household with a net worth of less than $50 million (99.9% of American households)

(2) 2% annual tax on household net worth between $50 million and $1 billion

(3) 4% annual Billionaire Surtax (6% tax overall) on household net worth above $1 billion

[End Warren’s proposal]

If this were enacted then Musk, Bezos, Brin, Page, Zuckerberg and others would face a 6 percent tax rate on the stock they own in the companies they created. They would lose control of those companies within ten years. A 2 percent wealth tax rate would allow the multi-billionaire owners to maintain control much longer.