So at first blush it may appear that employees are receiving less, but perhaps it's the people investing capital that are being rewarded.

This was my thought as well.

If productivity, or output per hour worked, rises faster than employee compensation, GDP can grow faster than earnings paid to workers.

That could cause employee compensation to fall as a share of GDP, as seen in the original graph, even if wages and benefits were continuing to rise in real terms.

So let's take a look at how median real weekly employee earnings have been doing:

St. Louis Fed (FRED): Employed full time: Median usual weekly real earnings: Wage and salary workers: 16 years and over (LES1252881600Q) | FRED

Median real earnings (which strips out skewing effects from high income folks) are currently at an all-time high if you ignore the COVID blip caused by so many lower paid workers temporarily losing their jobs, which raised the median temporarily at the time.

But it's an interesting question why a relatively small share of the massive productivity gains in recent decades have translated to higher earnings. One thing to note though is earnings don't capture employer-provided benefits. It's possible that increased benefits (driven by escalating healthcare costs for instance) could be absorbing some of the increase that would otherwise have shown up in income.

Despite this though, the US seems to be doing OK, ranking #2 in the world by median disposable income, and it's not a close race. The US is topped only by Luxembourg, a tiny, unusually wealthy country.

To add to that, a surprising analysis recently estimated that the poorest state of all 50 US states, Mississippi, actually has a higher median disposable income than many high income European countries: Ireland, Finland, France, Italy, the UK, Spain, and the OECD as a whole:

mises.org - Britain france and spain poorer mississippi