We live in an over-promoted society
And the basic reason for this is a two-fold consequence of the industrial revolution:
1. The industrial revolution led to a rapid increase in economic productivity which led to increased per-capita wealth, reducing mortality rates (especially childhood mortality) and driving an expansion of the population.
2. The reduction on childhood mortality differentially applied to the children of the poorest, least intelligent, least hard-working, most impulsive, sickest - i.e. the least 'fit' in biological terms; such that after a few generations reproductive success became almost entirely a matter of fertility; and the wealthiest, most intelligent, hardest-working, most diligent and healthiest used modern technology to reduce their fertility to significantly sub-replacement levels.
Therefore, at the same time as economic opportunities were expanding (due to increasing productivity) the abilities of the population were declining - resulting in a double-whammy of over-promotion.
Offspring generations who were less cognitively competent than their parents generation (and, offspring who were indeed, on average, less cognitively competent than their own parents - due to the accumulation of deleterious mutations) - would nonetheless end-up working in a job requiring greater cognitive competence than their parents.
Such that there has been a perceptible decline in the competence of each functional stratum of complexity to make the over-promoted society in which we live - a society where (for instance) people who would make a poor-quality mid-level bureaucrat are actually allocated to jobs requiring a high-quality high-level bureaucrat.
And of course they can't do the jobs, so the jobs are either done badly or simplified towards a level where they can be done adequately - by enforcing routinization, protocols, strict procedures and the like.
In the Middle Ages the situation was the opposite - the Middle Ages was an over-competent society.
Most of the children who survived to adulthood were children of the middle and upper classes - yet there were insufficient social niches at their parents' level for them to occupy, since there was essentially a fixed number of positions at each occupational level: a fixed number of Priests, clerks, merchants, skilled craftsmen etc. - and any expansion of their numbers would simply suppress their standard of living.
Only a very small proportion of the children of the lowest classes, the mass of peasants, would survive to adulthood. (I will leave out the small number of landed aristocracy from this analysis.)
This meant that there was continual net downward-mobility; with the children of the skilled middle class necessarily going down the social scale to become low-skill or unskilled landless farmers, serfs, peasants and the like.
Since cognitive ability and personality is mostly hereditary; consequently, people at each each social stratum tended to be over-competent for the jobs they did - in cognitive terms they could easily master their jobs, and could have worked at a higher level - but could not do so because there were no available occupational niches.
This was the world up to about 1800. A world in which there was more talent than could be used. Where almost everybody could easily master their job.
There was no point in training or educating more people for skilled middle class jobs, because these jobs could not be expanded - there were as many people in skilled jobs as was 'needed' (i.e. as many as could be paid for).
This was a society of great demand for education from the over-competent lower orders, where the ploughboy or shepherd could be a great poet, of hunger for books and information, where there was great scriptural and devotional knowledge and long complex sermons in church, a society of mutual and self-education, and one of widespread 'home schooling' (there was a high level of home taught literacy in England long before there were many schools).
After the Industrial Revolution suddenly there was more money, more food, more resources - and there was all this over-competent talent apparently 'trapped' in the lower orders.
And this was the world in which socialism emerged - socialism in its earliest form of a meritocracy of the talents; a society in which the highest positions would be open to those of ability as well as (or instead of) to those of noble birth; socialism as in essence a facilitating of the movement from the middle to upper class; but also - and increasingly - rationalized by facilitating the movement from lower to middle classes.
But now, a century and a half down the line - or more - we have a very different world in which there is no problem of talent trapped in the lower orders, but rather of a generalized deficiency in the kind of abilities necessary to renew, sustain and run the kind of complex society we have inherited; and in which there is a continual dumbing-down of public discourse and educational standards, rampant cheating in exams that are anyway undiscriminating with respect to intelligence, widespread lack of enthusiasm/ resistance to education - and all the rest of it.
This (and more) is the result of the transition from an over-competent to an over-promoted society; ultimately driven by demographic change combined with a reversal of the direction of natural selection from advantaging greater 'fitness' to lesser fitness...
Or, more exactly, a change in the nature of the 'fitness' that it has selected to such an extent that modern biological fitness - meaning those traits which reproductively are advantaged - is almost the opposite of what fitness was 400 years ago.