USA, Canada /
advice on where to live in Canada [64]
Where does it say that?
US - IRS Form 8829
Canada - The Canada Revenue Agency forms T2124 and Form T2032
Americans pay less taxes in general so it is conceivable that your example of electrician would allow him to pay just a couple thousands of dollars in taxes on what is effectively the income of $80K to $100K. All perfectly legal.
In Canada, on the same income, given a good accounting, business and record keeping practices you may, in some cases, get away with about $10K in taxes. Further, in Canada we have a federal sales tax (GST). for an average Joe working for someone it's a drag since every purchase and service costs 5% extra. Not so if you have a registered business. The techinque is kinda complex, but when you're done, as a business owner, you end up paying little to no GST on your purchases.
That's for sole proprietorship. If you incorporate then it may be even less in both countries.
Many businesses pay nothing for years (due to initial investment cost, decalred overhead costs and other legit factors). After a few such "skinny years" the revenue agency may declare your business a hobby and you are no longer allowed to operate under that business name. In this case it may be possible to register under a different name and slide on for the next 3 to 5 years. Again, all perfectly legal.
You're 19, still a kid. Look around. No, the roads are not paved with gold, but if you get a contract to pave some of them you'll do well.