This is a good essay. It is a bit long, and takes some time to get to the point, so I'll summarize and add a few comments.
There are two types of goods, material goods and positional goods. Material goods are things like food, clothing, and medical care that directly improve the physical condition of our lives. These things have gotten much cheaper as technology advances, and will continue to do so in the future. Positional goods are things like famous artwork, admission to an elite university, or a lake house. They mainly serve to improve your social status, and technology will not be able to make more of them.
As our material wants and needs are satisfied more and more cheaply, people focus more and more on positional goods. If you are hungry, your goal in life is to get enough food. We can, in principle, do this for everybody, making everyone equally well-off. But material equality never actually makes people happy. When material needs are met, they typically start chasing positional goods. But we can't give these to everybody. The number of positional goods is fixed. This is inevitable. If they weren't rare, they wouldn't be status symbols.
So as we get richer and more technologically advanced, society appears more and more unequal as it becomes harder and harder to give everybody what they want. If the life goal of everyone in the population is to make sure they and their kids have enough to eat and a decent place to live, then everyone can be satisfied. But if everyone's goal is to send the kid to Harvard, than 99.99% of the population will be disappointed.
So we should expect more and more complaints about income and social inequality, even as technology makes everyone's standard of living go up.
I'll add that material goods are probably less likely to inspire jealousy and zero-sum thinking. If your neighbor has plenty of food, he hasn't taken anything away from you. You can work and earn money and get just as much food. But if your neighbor has a Picasso, then you cannot have it. Hard work that creates material goods adds value to the world, making everyone better off. But hard work that chases a positional good doesn't do anyone any good, because nothing has been added to the world.
Thankfully, this is a problem that individuals can easily solve on their own. Train yourself to stop caring about status symbols and positional goods. If you know how to be happy with the material comforts that are getting better and cheaper all the time, then the future will be a very enjoyable place for you. But if you insist on acquiring things that your neighbors do not have, then the future will be an endless rat race for you.