There is a curious collusion between elites and the working class that can actually arrest progress and stop wage growth.
You wouldn't think that the working class - people in the lower middle part of the income distribution - would willing collude with the wealthy to perpetuate what might strike others as a fairly basic income. And yet ...
There are a few concepts that come into play in this attempted explanation: extractive institutions, insecurity, and gales of creative destruction.
Schumpeter immortalized the term, "gales of creative destruction" as a means to define how markets simultaneously create the new - "look! a horseless carriage!" - and destroy the old - "look! Clem's closed up his horse dependent carriage shop!" By most every measure, these gales of creative destruction are the source of progress but they also threaten the folks who are currently making a perfectly good living selling the old, soon to be obsoleted product.
When you are working class, you're not in poverty but you are not secure. Over half of Americans don't have enough savings to cover an unexpected expense of $500. For these Americans losing a job and then getting retraining for a new career are simply not a practical choice. (It might be a necessary one but it's not a practical one.)
Finally, there are extractive institutions (I first encountered this concept in Acemoglu and Robinson's book Why Nations Fail) that leave workers within them at a subsistence wage. The owners or rulers of these institutions - whether the Spaniards who ruled the encomiendas or Robert Mugabe over Zimbabwe - extract all the profit from the institutions. Among the many problems with extractive institutions is this: no one has incentive to conjure up the gales of creative destruction to create the next, best thing. Any breakthroughs in process that workers could adopt to raise profits will just flow to the pockets of the owners. People within the system won't make any more whether they work harder to smarter so they tend not to. People who control the institution aren't really interested in any progress that could create the gales of creative destruction that suddenly obsolete their system so they tend to resist progress or improvement. There is a huge difference between the poor people within the system and the rich who rule it but they do share this: they feel threatened by change and will resist it.
Progress steadily makes life better for everyone. It also tends to abruptly make life worse for at least a few: the unfortunate stockholders in Kodak when Instagram comes along, or worse, their unfortunate employees.
Politically, this is tough. The folks who lost their jobs to automation or outsourcing are acutely aware of this. The folks who are buying 1" extra of TV for 90% less are less aware of this and less passionate about it. Progress's creative gales are more evenly - and imperceptibly - spread across a population than are its destructive gales.
An aversion to change that might bring in the gales of creative destruction is shared between the insecure working class and the owners of extractive institutions who profit from the status quo. They make for odd bedfellows but both share an incentive to resist free trade and new technologies.