For simplicity, let's say that we have four different income groups. The minimum wage group (25 million people in this group), the $15/hr group (100 million workers), the $50/hr group (25 million workers), and the owners of the means of production group (1 million owners) who have unlimited incomes.
Now lets say that I start out in the lowest paying group, and eventually, by improving my job skills and saving and investing, make it up to the "owners" group.
If nothing else changes, other than my personal ability to move up the ladder, our aggregate economy (wealth) is no better and no worse. That is what is to be expected if we (in aggregate) don't improve our technology any, and don't become more productive as a nation (GDP stagnates).
However, if we do become more productive per work hour as a society, and/or if GDP increases, then all income groups should increase in income and standard of living at about the same rate, regardless of whether or not individuals are moving up the ladder on an individual skill level bases.
So way back in 1914, maybe the average entry level wage, adjusted for inflation was $2/hr in todays dollars, the next group had an average wage of $4/hr, the highly skilled workers had an average wage of $7/hr, and those in the owners group averaged making $100,000 a year.
If the fruits of us becoming more productive per work hour (regardless of the cause of the improvements) didn't get shared by all income classes (they all went to the ownership class), then EVERYONE other than the rich would be poor. We would have no true middle class like we do today. Is that the world that you would want to live in?
Just a guess based upon statistics, but most likely you are middle class. You may be upper middle class or lower middle class, but if the fruits of our increasing productivity hadn't been shared between all income classes, today you would be poor. You wouldn't even have access to the computer you are using, let alone being able to afford to own it.
During the middle of the 20th century, roughly from about 1933 til 1975, all income classes did increase in income and wealth at about the same rate. Your standard of living and income level today, regardless of what income class you are in (with the exception of the rich), was established during that time period, and hasn't really changed much since. During the mid 1970's, something changed in our income distribution system, and suddenly most of the increases in income started going to the top income earners, and the middle class stagnated. The middle class has been pretty much stagnated ever since then, regardless of who was POTUS or who controlled congress. The point when income growth distribution changed is often refered to as the "Great Divergence".
If we could return to the economic income distribution gains of the middle 20th century, then your income would start to rise at about the same rate as our per work hour productivity, even if your individual value or skills didn't increase. If your individual skills continue to increase, then you would simply climb the economic ladder more quickly than you can under our current situation.
The chart below does a pretty good job of illustrating the Great Divergence: