A friend of mine told me that executives and directors in many publicly listed companies sell shares and accept money from index investors. Then they plunder this money by accepting bribes from unions to lift wages of workers. They also accept bribes from corrupt politicians to raise company taxes to help fund election campaigns to keep them in power. The union leaders are able to "negotiate" a higher wage and get performance pay bonuses. The politicians too raise tax revenue to use to help them stay in power. The executives take bribes and pay themselves large bonuses and salaries. Everyone wins except the shareholders (including index fund investors).
So why then do people keep investing? Why do shareholders keep plowing money into the company only to see it being plundered? Because they are sold a dream. By telling investors to invest for the long term, there is no accountability. Index fund investors keep plowing money into stocks like lottery players keep plowing money into tickets.
Buying and holding in equity index funds worked in the past because we were living in an era when the size of government was small. Today, the size of government is large and, let's face it, government is controlled by a network of executives and directors of big corporations whose objective is to create wealth for themselves. Hence they use the power of government to seize the revenue of corporations and distribute it among themselves. They are looting shareholders and selling them the opiate of the investor masses (i.e. "in the long run everything will be okay").
If you don't believe me, look at the statistics on the size of government. It has increased massively. Furthermore, the dividend yield on S&P500 companies used to be high but has fallen to almost nothing.