People have been saying "The rich get richer and the poor get poorer" for almost 200 years. To illustrate the absurdity of that, recall that there were few rich people then - the Cabots and the Forbes had just started making money - and only those very few had reliable food year 'round. As for the poor, think Dickens London. Think slavery. Think frontier. Two years ago I discussed how recent generalised prosperity is.
In the short run, if you take a very limited measure, you can indeed point to rich getting richer and poor getting poorer. Life is not always fair, the powerful press for advantage, and the children of the well-off in every generation have a leg up on the children of the poor. But even the poor have luxuries the rich did not just a few decades ago. My grandfather died of prostate cancer in 1967. He was comfortably upper middle class, the first CPA in NH, and treated immediately at the best hospital in the state. Everyone in America gets better medical care now.
Yet I am worried about the future. Two-parent families produce disproportionate numbers of the well-off, automation slowly eliminates jobs, and wealth may be increasing in scalability, narrowing the beneficiaries. Though most welfare recipients go on to have self-sustaining and even prosperous lives, there seems to be a slow growth in the families on permanent relief. Given the technological advances likely to keep appearing every decade, it is unlikely that the poor will be poorer in an absolute sense, but they may fall farther and farther behind the wealthy. This leads to perceived poverty and dissatisfaction.
Yes, we should all be bigger people than that, and rejoice in our own improved standard of living without regard to what happens to others, but we don't seem to be built for that. Other people getting rich often strikes us as deeply unfair. This likely intensifies as one's distance from the top of the economic heap grows.
I have some hope that the phenomenon of the Long Tail will provide at least some rescue. Amazon has kept many books in print that would have simply vanished to the remainder bin under the old system of brick-and-mortar bookstores and their limited shelf space. Many things that people make or sell can last longer with less overhead now because the universe of potential buyers has increased by several orders of magnitude. Multiple small streams of income may become more common.
Even more hopefully, things other than money may increase in the satisfaction they bring. With basic needs met, people might be increasingly willing to be pleased by the acceptance or admiration of a small group of the like-minded. We see this in hobbies already, where historical re-enactors, cellists, and dwarf-tree enthusiasts have each their own circles of familiarity and notoriety. These become like villages, and older rules of sociability may return.
For money was not the measure of all in most societies. Prosperity was always desired, but wealth was not a guarantee of admiration. Personal qualities of charm or talent were noticed, and dare we say it, virtue could be a measure of worth. Money isn't the measure of all even now, of course, but it seems to have taken a more dominant position in the early 20th C and grown in importance. Perhaps that was a consequence of increased mobility and communication across distance, making the most easily observable qualities - wealth and beauty - more important.
Multiple long tails of worth, some bringing in money, while others bring social connection, information, spiritual uplift, or status. After the Singularity, this may be the model for human satisfaction