Your comparison is nice, but it does not get to the heart of this debate. My grandfather built in 1955, with a lot, a lot of his own effort... and still had to pay more than ten times his annual net income for the house... even though most of the work was done by friends without payment. Back then, almost everyone knew a bricklayer, carpenter, electrician, etc.
When I read here that a large part even hires a professional company for the simplest tasks, like hanging wallpaper and putting paint on the wall... an acquaintance paid 15,000 EUR for Q3 (which was not necessary at all, Q2 was already great) and wallpaper...
No one should then be surprised... my grandfather helped with the masonry... and with the roof truss... and with the ceilings... in every trade.
Imagine the IT specialist throwing a tile to the roofer... unthinkable. That’s why building is expensive... because no one wants to "build" anymore... they want to "move in" ;)