Are these real? Let us assume that share price of a company goes up and thus the "wealth". What can I do with this wealth? The moment people try to realise the wealth by selling the shares, the prices are going to come down. Market ecomonomics - share prices will come down when there are sellers and go up when more people want to buy. Which means that the wealth is a mirage. When I go near it it will not be there anymore. Can I use this "wealth" for creating real wealth? Let us say I pledge the shares at the current high prices and take a loan. Let us say I buy some real assets. This is fraught with risk because the moment the prices come down. I will have to repay the loan which I took and if there is no other option then I will have to sell the asset to pay back the loan. So I cannot use the "wealth" to create real wealth because it is very risky.
So of what good is this wealth and market cap. At best it is a feel good factor making one feel like a king. But one needs to beware that one cannot and should not act like a king because then one will become a pauper.