> It's no secret that real wages have remained stagnant for most people for over 40 years
Real wages haven't remained stagnant. That's one of the great intellectual frauds going in economics.
There is a rather incredible failure to account for the dramatic demographic change in the US over the last 40-50 years, which has massively debased what would otherwise be a higher median and average wage, as well as higher figures for the middle class group. How can we see that data in action? Well, other than being obvious and logical given the context, you can see it by looking at the white demographic then vs now. The white demographic that used to represent essentially all of the middle class circa 1970 or 1980, no longer does. The white demographic has moved up in income, while the hispanic demographic has rapidly taken over an ever growing share of the middle class group. You can see this by looking at the white median income vs the national median income, they have diverged, whereas in 1970 or 1980 they were far closer to being the same thing. This effect will get more and more prominent by the decade (see: the latest census). There has been a rather dramatic demographic shift, that has involved tens of millions of poor low skill immigrants from primarily Latin America moving to the US and having to start from near zero economically (very little education, very little in the way of higher value skills, and often not knowing English). It can take a long time to build higher income levels or wealth from scratch, in a country entirely foreign to you, and when you likely don't even speak the country's dominant language. This has all happened while simultaneosly the primary middle class group of the past, the white demographic, has seen a record low population expansion over the last few decades. What does that mean? It means the newer hispanic demographic is that much more impactful on the median and middle class figures that are so often referenced, than otherwise would have been the case had white demographic expansion trends continued from the 1970s or 1980s.
The clowns in economics go about pretending the US of 1970 is the same US of today, that nothing has changed demographically, that there has been no mass immigration from Latin American nations over the last four decades, and that that doesn't considerably debase the middle class income figures or the median figures.
When one talks about how wages have performed over decades, accordingly, you have to ask: for which groups? Because the demographics of the US have changed considerably in 40-50 years. You have to know the story you're inspecting.
So a white middle class family from 1970 or 1980, how are they doing now? Have they seen progress? Has their wealth and income climbed? (yes, the figures we have say it very likely has)
A poor immigrant from Latin America that arrived in the US in 1994 with $0 and little education - if they're now in the US middle class, that's a good outcome from where they started from. How about second generation Americans whose parents were from Latin America and were part of that major immigration trend? If their parents arrived with little or nothing, how is the second generation doing, how does that progress look?
You can't just say: oh but eg middle class wages haven't moved in real-terms in 40 years. That's very badly dropping context. The US hasn't been static over that time. You have to understand what the story of the people you're talking about is; who are you talking about?
If your median numbers tread water in real-terms while you bring in tens of millions of poor low skill immigrants, you're seeing a remarkably positive outcome in fact.