No laws are voluntary. They are all enforced under duress. Men will come to your house and jail you if you don't follow them. That's why they're called "laws", not "options".

I think you two are in agreement.

No. You entered into an agreement with your employer and the US government when you were hired. You gave them permission by consenting to work within the system and you probably filled out some sort of form with a W in front of it.

You may work outside of the system.

I made no such agreement with the government. You are manufacturing consent where none exists. The sole reason I pay is because of the threat of force, the promise of a gun to my head if I do not. There is no consent.

Who will put a gun to your head if you stop working in the US?

Local cops via MLAT wherever I am working, as I owe US taxes regardless of where I earn money, a fun misfortune based on my location of birth.

Failing that, local cops, when I am working nowhere and have to resort to stealing food to survive.

Starvation, death by exposure, death from preventable disease and the like might not literally be guns, but the effects aren't that dissimilar and they are all consequences of not working in the US. There's not exactly a robust social safety net here.

I think people overstate the dangers of moving to Canada

WAIT. You entered the US? You're not a citizen? You're complaining about our rules after we let you in?