In wonky econ terms price is a separating hyperplane. What it tells us is that it would cost more than the market cap to buy all of the asset from the current owners and the current owners would earn less than the market cap selling it all into the market.

I could be wrong, but doesn't "realized market cap" fix exactly that?

This reminds me of when Socialists want to tax the rich.......but most of their wealth isn't realized, it's tied to stock in their companies.......which will tank as the dump their shares.