That suggests there is some form of conspiracy theory, when I think in reality it's more a case of a number of forces coming together. One of these is globalisation, and this has given companies a much larger potential market whilst also keeping costs relatively low, especially with technology playing such a major role. This has meant increased competition for labour (from both man and machine) has helped keep wages down, but the growing sales reach has meant higher returns for those with capital.
The second major trend is to do with this automation and technology. The stories are legion of companies like Instagram being run with a handful of employees vs the tens of thousands who lost their jobs when Kodak went to the wall. Many of the big new companies of recent years have employed fewer employees per £ of revenue than has traditionally been the case, in large part due to technology making each employee much more productive. What's more, the network effect has made it easier for dominant companies to entrench themselves in the market, with startups aspiring more towards acquisition than disruption.
This has had a particular impact on the lowly skilled end of the market, as these jobs are usually the first to be either automated or outsourced to cheaper places. Indeed, the UN did a report recently looking at the impact of automation on such jobs, and predicted significant disruption in the developing world, as many of the jobs that were outsourced there will soon be automated. It makes the claims by Trump et al that such jobs will be brought back to America (or Britain) rather weak. The work may come back, but it will increasingly be done by machines.
Now, here's the thing that doesn't get spoken about often, as when we think of economic systems the dialogue seems to only ever be about producers (workers), but of course there's another side of the coin, namely the consumer. The consumer has benefited enormously from the trends outlined above, and we can now buy a vast range of goods at prices that would have been unheard of previously. I think that's something we have to keep in mind when discussing the virtues of any economic system as it isn't all about workers, and consumers are often forgotten about.