Really interesting topic, and more critical than many realise. Now I am an economist, and in this sense "a little knowledge is a dangerous thing" insofar as I can see where these sorts of pay inequalities are likely to go.
First, let's set the scene.
"Market forces" or "free markets" are held by many to be an intrinsically good and efficient system of allocating resources towards competing ends and distributing rewards to those resources. The devil is in the detail.
To be specific, market forces tend to return the optimal rewards to whatever is the dominant input into the productive activity. In the 20th and early 21st century the biggest input was labour, and market forces allocated and rewarded labour; efficiency gains were passed to labour by way of pay increases and (to some extent) bonuses.
This is increasingly not the case. Now the dominant factor is capital (i.e. machinery or automated systems) and this is the most important input. So, it is no surprise that market forces direct increasingly disproportionate rewards to the owners of capital, e.g. automated technology. For example, the owners of a factory save labour costs by sacking the workforce in favour of machines. The savings flow to the owners of the technology is retained as increasing remuneration and bonuses. These relative few live well at the expense of a rising proportion of disenfranchised people, previously used to stable employment, but now living in the "gig economy" or lesser paid work.
I have grown to refer to the pressure point that is approaching as the Star Trek or Bladerunner Choice. In the former we engage with technology to become more enlightened, and free to follow our interests without fiscal concerns. Here the sun is always shining and your hair looks good. In the latter, large corporations progressively enslave the majority and trap them in a low-income subservience from which they will never escape. In this world it always rains and your hair has long since fallen out.
I think the existence of disproportionate executive remuneration at the same time as widescale adoption of technology over labour means we are heading towards The Choice, but quickly.
Other things being equal, and leaving people to make there own choices, we can look forward to rain and bad hair. To beat this, and turn down the road to Utopia, we need concerted action on a society-wide level. Governments acting in unison.
As a capitalist, it is painful to say this, but if we are to continue to operate a society for all people, we are going to have to use direct taxation to redistribute the rewards of automation away from owners of capital, and towards otherwise disenfranchised individuals. This is the only way to make the Star Trek choice possible. Is this anti-capitalist? I don't think so. It may just be that we are creating a world that, because of its technological sophistication, has passed beyond such antiquated concepts as "capitalist", "socialist" (to name only two).
But how do we calibrate this? How do we deal with the secondary problems that emerge from people having no purpose? Although these are issues, it is better to have these and seek to solve them than to continue down the path we are going.