Thank you for your reply! The US company actually hires me to be a full-time employee working remotely, like 9-6, 5 days a week. So I thought in this situation I cannot categorize myself as a freelancer.Why incorporate? Why not just be a freelancer without incorporating? This is a very informal link, but has some potentially helpful info https://diaryofatorontogirl.com/canadian-income-taxes-freelancer/
I also don't understand why you'd be "able to be hired by this US company if I incorporate as a company". Really? Perhaps it's just semantics, but seems like you'd be a freelancer (rather than hired by the US company) and you'd invoice them, and they'd pay you (but not as an employee).
So far all of my understanding is that if I want to be an employee for them, the only other way (besides through PEO) I can do it is the incorporate myself and start a "personal service business" on purpose, so that I can get paid and pay the same tax rate as my individual income tax rate.
If you know other ways which can help with this situation, please advise! Thank you!