Earlier quoted context omitted.
If by 'efficient' you mean 'most consistently profitable', then no, neither markets nor a 'flexible corporate environment' promote actual efficiency. In that kind of environment - which is not too dissimilar to the one we're in - corporations simply hoard money to no great end, and markets crash unless they're propped up by public subsidies and hand-outs. This distorts the wider economy and makes real efficiency less…
On the contrary, 'providing the greatest possible benefit to the greatest number of people' is a central focus in economics. Start with Pareto efficiency and go from there if you want to see various ways in which economists actually define and study efficiency.
Partially it's because that goal is far more difficult and complex than the simple aspirations of Greater Taylorism: to increase shareholder value. It's much easier to increase a stock price than it is to actually provide value for a large number of people, which leads to cases like IBM who spends billions buying back their stock while the actual value of their products declines to near zero.