If you look at real incomes over time, they've been stagnant since the dawn of time; or at least as far back as we have kept track.

There was once wage growth because wages started from zero. It wasn't that many years ago that people didn't sell labor, only things. As we have transitioned into a labor economy, wages started to become a larger portion of one's income. To the point that nowadays more or less 100% of the average person's income is from wages.

So, with incomes and wages now being effectively equivalent, there is no room for wages to grow further. To do that now, incomes would also need to rise, and that has never happened.

Productivity has continued to rise since, but on the back of automation, not as a result of humans becoming even more productive laborers.

Take a look at the size of government over time. Where do you think the money comes from to pay for that?

This isn't true for the US. The chart that purports to show this is misleading. Essentially, there are problems with the usual chart: the two lines are indexed to different inflation measures, and the wages line excludes certain highly compensated occupations which have been experiencing significant earnings growth (probably because these occupations are where the productivity growth is happening).

Edit: Actually, even more issues. https://x.com/AwayBerk/status/1483564925213683719