No, I think this still this isn’t an accurate framing of history. Managers have always had a completely different job than the people they manage. If anything, having a lot of managers that are in the trenches, writing code for example, is the newer trend. Since the Industrial Revolution, managers typically oversaw work but did not do the labor. You could ask some managers what they do all day, but once you get some management experience, you will start to understand what managers do all day and how there’s enough to do that getting technical work done is relatively difficult, and might compromise their ability to manage well.
Here are some pointers to the evolution of management over time that you might find interesting or enlightening:
https://en.wikipedia.org/wiki/Henri_Fayol#Functions_of_manag...
https://en.wikipedia.org/wiki/Scientific_management
https://en.wikipedia.org/wiki/Hawthorne_effect
https://en.wikipedia.org/wiki/Peter_Drucker
The typical ratio of managers to laborers has definitely increased over time. 1:5 is higher than average, but 1:10 is very common for knowledge work. There are many reasons why this is, team building incentives are only one of many. But one question you should ask yourself is why you even care. Companies are free to function any way they want to, and they pay you to contribute to their choice of structure. Given that all modern large companies function this way, and also make money, maybe it’s worth starting from the assumption that it evolved this way for a reason? See Chesterton’s Fence.