Part of the problem I have with graphs like this is that they don't differentiate between paper wealth, being able to get a loan against the paper wealth, and hard assets (real estate, vehicles, cash).

Let's take a personal anecdote for an example: I joined a startup when it was early-stage, stayed for a few years, and exercised my stock options when I left. The startup is now "successful", but still private; my shares have also surely been heavily diluted. I have no idea when I'll be able to sell those shares or how much they're really worth. I have no way of turning those shares into quality-of-life improvements for any foreseeable future. Do they make me "wealthy"?

I don't think most Americans have a problem with rich people buying nice houses and nice cars, and using their wealth to pay for private staff. I think the real problem is how much of the wealth is allowed to stay off public markets. Cargill is worth more than $50 billion and its stock is not available on public markets. The growth in wealth of most AI companies - Anthropic, OpenAI - happened off of public markets, and so none of it trickled into the American middle class by their retirement accounts. Venture capital is keeping companies private for longer because, quite simply, none of the investors need the cash to pay for their cost of living, so they're quite happy to let paper gains continue to live on paper.

If your company has revenues of $X million a year or more, you should be forced to make public financial reports (effectively forcing you to list stock on a public market). Period. I think economists will naturally disagree on how much X should be, and that's fine, but I have little doubt that there should be a line like that, somewhere. Concerns about public markets forcing short-term thinking are a different problem, one addressed by mission-lock implements (Eric Ries's recent book Incorruptible is great here). Public markets ensure that gains in wealth are shared more broadly across the economy and increase tax collection by incentivizing more frequent buying and selling of the underlying stock, since those are taxable events.