There is a structural problem within most of the industrialized world's economies. It is most pronounced in the United States of America.
It is an imbalance between the amount of capital available and the level of incomes available to consumers.
Simply put, there is too much capital and not enough income.
The evidence is clear: historically low real [inflation adjusted] interest rates and stagnant real consumer incomes.
In practice it means that capital is available for projects that promise low profits. Historically, the expected profit rate has driven capital toward more profitable, hence more efficient, projects.
Thus some investment is driven toward marginal projects - which do not contribute materially to the economy's well being - since they are the projects available.
More damaging is the trend toward monopoly control of markets and supply chains. Monopolies are incentivized to provide fewer products at higher prices than a competitive market would absorb, thus reducing employment and incomes.
Monopolies and oligopolies also attempt to control the regulation environment so that their dominant positions are sustained. One needs only to look closely to the banking and financial services industries to see the pernicious effects of such regulation control.
The problem is hidden today because the numbers are good - low unemployment rates and GDP growth.
But, these numbers are not sustainable unless consumers have the real purchasing power to sustain them. Real growth happens only when consumer demand is strong.