To earn that kind of money as a plumber you would need to either work your way up over the course of roughly 15 to 20 years at a very generous plumbing company, or be an independent plumber with next level marketing skills.
The average plumber, pipe or steamfitter just coming out of their training is not going to get anywhere near 300 000 a year.
TLDR: Chance favored the prepared skill set. No fancy degree required, just results.
PS Before that, I blew a boring blind-allocated gig at Google insisting that GPUs were about to play a huge role there a year before they acquired DNNResearch. I even tried to join the very beginnings of the Google Brain team but they didn't have any openings or the budget/willingness to make one for me.
I'd be surprised if the take-home on $150/hr is even close to $60/hr.
Are you just making up numbers? You've asked for sources, other commenters (including myself) have provided several, and the sources disagree with what you're stating spectacularly. I'm baffled by how confident you're being about something that, as far as everyone can currently tell in this thread, is plainly incorrect.
...how many plumbers do you personally know? The reason everyone in this thread is pushing back against this is because the suggestion is ludicrous. It doesn't make sense in terms of market dynamics - the barrier to becoming a plumber is significantly lower than the barrier to becoming a software engineer. That's not intended to demean the profession, it's just true - you do not necessarily need any education (and the profession embraces this far more than tech does, which is itself progressive on that point) and requisite domain knowledge is not as extensive or as rapidly changing as software engineering. You need technical knowledge, but unless you're taking the most complex plumbing jobs and the most mundane engineering work, they're simply not comparable.
Some plumbers do well, particularly if they own their own business and are thereby successful entrepreneurs. But you can't judge the typical outcome of a professional career by the entrepreneurs who use it as a basis for their business. The modal plumber doesn't earn anything resembling $300k/year - according to the BLS, there isn't a single state where the average is even $100k.[1] Where are you getting your data, from how much they're billing you when you have someone fix a problem in your house?
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1. https://www.bls.gov/ooh/construction-and-extraction/plumbers...
https://money.usnews.com/careers/best-jobs/plumber/salary
When the data disagrees with your mental model, consider re-evaluating your mental model.
The amount a client pays per hour for labor != the takehome pay of the person whose time you're ostensibly being charged for.
Revenue is not profit, and "price per hour for labor" != "hourly rate I pay my laborers". This is even true in owner-operator businesses. Furthermore, in bursty markets, "annual income amortized over career" != "my hourly rate multiplied by 40-60 multiplied by the number of weeks I want to work".
The numbers from my links are INCOME, not "what the business charged the client".
:-)
Why keep insisting on proxy variables and anecdotes?