A good chunk of why software engineers get paid well is because most people don't like writing code. It's not just because the businesses scale well, it's because it's an undesirable job for most.
By that logic, the cleaning staff in your local adult movie theater would be millionaires.
There's a limited supply of people with the education and life opportunity to become engineers, but still the vast majority of those don't despite the pay.
By that logic, the cleaning staff in your local adult movie theater would be millionaires.