Comment by Mezzie

There's a huge difference in where plumbers vs. SWEs live, though. You have to compare the actual purchasing power. SWEs are more likely to be located in HCOL areas and therefore have higher salaries because SWEs need the infrastructure cities provide. Whereas there are plenty of plumbers who live in rural areas.

I have no idea how that comparison would shake out, or if the rise of WFH for tech people would/will change it, though.