IDK, the original article talked about the stock market. On that exchange, market capitalization is measured and is a proxy for everything going on with public companies. What you are talking about in 1) and 2) is some non-existent market on which total equity and debt with vastly different characteristics is valued on one shot. What exchange do you have in mind here? The only time you fully measure all the effects to calculate the enterprise value is when you are buying the company outright. There are several practical reasons why you don’t measure and trade on the enterprise value of the listed companies. To list a few

1.On the equity side you only know the prices of outstanding shares, how will you value the non-traded shares and options? There is no simple measure to assign the control premium on a single company much less the entire stock market. This doesn’t include debt that might convert to equity on different schedules.

2.On the debt side, debt can be convertible to equity, have different seniority, payment schedule, liquidity and risk profiles. What does a consolidated number tell you? Not to mention off-balance sheet commitments and the fact that debt for some sectors like a financial company might not make any sense. What does the enterprise value of Bank of America even mean?

3.Even valuing cash has problems if you are like a US tech company with billions abroad that might be subject to myriad tax rules.

Finally with 3) you talked about private companies, at that point you probably need to look at SOE in China as well. Now you are looking at total wealth and not the stock market.