It must be pointed out that, over at least a century or two, technology has been improving at the same time that median, mean, and bottom percentile incomes everywhere have been increasing. This seems to be nearly irrefutable evidence that technology doesn't itself make workers poorer.
Technology and knowledge makes society wealthier: even poor people all over the world now have enough wealth to own a small device called a cell phone that lets them have a rich life in terms of entertainment, access to services, banking, communication with their loved ones, etc. BUT, that doesn't not mean we all get paid more, because what money does is that it lets you buy somebody else's time. But obviously if you and I both produce more, it can't be the case than now I can buy more of your time than before.... We can both buy lots of things that our parents never even dreamed of, but we can't buy more of each other's time....
Its still definitely true that if your folks work manual jobs, you will get a higher income than they do because you will get a high productivity job. In fact you see a lot of uneducated people being supported by their children with reasonable jobs and being helped with the phone and the google maps and the Amazon shopping thing. The issue is that older people, on average have moved up the command ladder, so they are doing management and maybe managing all these youngsters that are super productive at the basic tasks that they are given. These youngsters are productive, but they are not the managers, and they couldn't be. Technology does not make them better at managing people, only experience and age give you that ability. So despite high productivity, they don't get paid a lot, specially since unemployment has been so high for so long. But, they will be paid a lot when they become the managers....
Of course, there are also differences in the distribution of income over time. Apparently, its true that the fraction of income going to workers (the "labor share") was low over the 90's and 2000's and also that general inequality within countries has increased. Also, young, low skilled workers, during this period suffered the brunt of the crisis, staying unemployed and learning less on the job that other cohorts. So, if you focus on the young, the low skilled, the ones that were looking for their first jobs between 2008 and 2011, you will probably find relatively low incomes. There are also individual skills that have been replaced by technology, like typists, or long distance operators.
Still, its hard to argue that the majority of the US young people are worse off in life than their parents.