This reminds me of a funny (probably illegal) thing that Max Fosh did where he made a company with an absurd amount of shares and got some random person to buy a share for $20 or $50 or something so his company temporarily became the richest in the world (technically) lol
It is A metric of the company, best could be argued, absolutely best is stretching it. When company value is based on hype, over promise and lies etc, the market cap becomes less relevant and the revenue/profit are better metrics for valuation.
Theranos was valued at 9B$, just based on hype and lies.
Weird that people argue about this. If the value of a company is being talked about, then stocks is what people generally refer to. Now, if you'd specify and talk about some other value, then sure, but if only "value" is being mentioned I see no reason to think it would mean something else than stocks.
stocks are unstable and they only provide actual value when sold. Thus, for some, it is at best an imprecise measure. Thus People don't like it and some simply refute the valuation. The fact that it remains the only viable source for valuation is not relevant to them.
Just a different PoV (world view as to what is valuable in life) which is not catered to by the available data.
A big part of trading stocks is assessing value independent of the stock price. You want to buy stock when it is undervalued and sell it when it is overvalued. Tesla seems to be in the latter position, IMO.