In my childhood in the Soviet Union “plumber” was what parents scared their kids with “if you don’t study, you’ll become a plumber”. And that profession was extremely undesirable and didn’t pay well.
Also in many SEA countries both professions aren’t paid well.
I think in North America it’s different because it’s highly regulated and barrier for entry is high.
What that framing misses is that a lot of plumbers have to fix situations where a sewer line ruptured and someone’s basement is covered in shit. Or like, you get called in because someone’s garbage disposal is clogged with something nasty, and the person won’t tell you what it is. Plumbers definitely should get paid a lot for what they do, though whether that’s actual true varies.
I'm sure the cost of his excavator ran into ~$1k of wear/depreciation over that day but two men basically cleared $5k in a combined 20 man hours.
If you can deal with poop you can make a lot of money. Doesn't seem to be much interest in that trade either, no one thinks to become a septic installer.