Well those are just the biggest/most relevant tech labor markets I could think of, roughly by GDP. I don't know much about Australia but couldn't comment there, thanks for the insight.
> I don't have insights into other engineering, but I think software engineers are overpaid. Would I enjoy being overpaid? Of course, but it's hard to say it's fair pay considering what people in other professions are making.
I don't think comparing pay across professions makes sense -- why compare a plumber or doctor to what a software engineer does? the outcomes are completely different, the risks are completely different, the upside/profit potential is completely different.
I lean towards considering software engineers as underpaid because the power of automation (whether software or hardware -- because you generally need some kind of soft/firmware to make robots move) is insane. If software engineers were ever paid a percentage of the revenue impact they generate (which is not how markets work, but I digress), software engineers would be paid much much more. I think it might be possible to compare across professions if you think of % of value creation captured let's say but it gets tenuous.
In the end the only "fair" determination is what supply and demand based markets dictate. They're not perfect, but they approximate other forces/influences decently enough. When those aren't enough, governments may need to step in to enact policy.