Some excerpts (italicized) from an article in The New Yorker:
When the banking system behaves the way it is supposed to...it is akin to a power utility, distributing money (power) to where it is needed...
Financing Vital Industries
The other important role of the banking industry, historically, has been to finance the growth of vital industries...
Vital industries like railroads, pharma, and autos among others.
Trading vs Investment Banking
For Goldman Sachs Between July and September of this year, trading accounted for sixty-three per cent of its revenue, and corporate finance just thirteen per cent.
The proportion of Morgan Stanley's business that was investment banking was similar at less than 15%. So these businesses have changed from businesses whose profits rose and fell with the capital-raising needs of their clients into immense trading houses whose fortunes depend on their ability to exploit day-to-day movements in the markets.
So what's the utility of many investment banks in their current form. Lord Adair Turner describes much of what happens on Wall Street and in other financial centers as "socially useless activity"...
A better balance seems needed. Far too much energy goes into what is, for the most part, "socially useless" (or, at least, economically mostly useless) in lieu of financing vital industries and providing the "power utility" function.
Check out the full article in The New Yorker.