It’s not at all an accurate analogy though.
People are thinking of a job market as if it is snapshot in time of a single company’s org chart, with one person at the top and more and more people in the levels below, stuck there forever. It’s not.
According to the Office for National Statistics, only 2.5% of jobs in the U.K. are low paid (earning less than two-thirds of the median hourly wage). In the pyramid analogy, this means the pyramid is inverted. There are 40 times more jobs at the top (the higher paid end) than at the bottom (the lower paid end).^
Similarly, around a third of low-paid workers are aged 16–21. When you include under-25s, it’s likely closer to half. This shows minimum-wage work is heavily concentrated among young people at the start of their careers, which directly contradicts the idea that most people remain stuck there permanently.
Of course some people won’t be able to do other work, and of course some people will choose not to, but there is very little evidence to support the idea that the majority cannot or will not progress to higher paid jobs over time.
^ note: in reality that inverted pyramid is more like a sphere if you actually did the graph, but that’s starting to over complicate it.