Its a
better metric than marketcap. Marketcap is just what a few people are willing to pay for shares, literally the one person at the auction house that bid higher than others and got SOLD to, except in the stock market everyone pretends to multiple that 1 share by the other 4.28billion and act like its an indicator of value.
Whereas net income shows what MANY people bought, and how the company is able to keep a bunch leftover.
And regarding "good", it's a good metric for value creation and the infrastructure for independence, as this has been unachievable before and always required a monopoly on power derived from the entire social contract of society and force. So it is merely interesting for it to occur in the absence of those things. It is not a comment on "good" in terms of society and whether the social contract should include a way to limit them, it doesn't factor that in at all.