In theory that's true, but in practice the people at the top deciding what's profitable aren't working for maximising public good, so it doesn't work anymore
Are you claiming there is widespread fraud in SEC filings?
If you are referring to many industries becoming controlled by a handful of large organizations, then people working in trading and finance have nothing to do with that. That is in the political arena.
But the same is true for many other professions. I also remember reading that the highest paid engineers are working for Google and Facebook to optimise ad placement. CEOs get paid a lot even if their company does things that harm society. There's an entire industry just to help large companies avoid paying tax.
A lot of things that would be good for people/society have no good way of really being profitable (unless lawmakers do something to rebalance the game to somehow help them).
And a lot of things that are profitable are objectively bad for society.
- Career politicians who are more interested in maintaining office than working for the public good.
- Corporate executives who prioritize profit/stock price over the common good. The Sackler family comes to mind.
- Financiers (of various types) who accumulate personal wealth to the detriment of the common good.
It's possible to be a good politician or a good executive and not be "evil", but there are enough notable examples of the worst of both that both careers are somewhat sullied in the public eye. And of course, it's all shades of gray.