Wouldn't Switching US healthcare to a Canadian system lower the debt faster than anything else?

Same old same old. When the facts disagree with ideology, American exceptionalism will be claimed as the reason why universal health care could not work in the USA.

It this simple, folks: you are paying to support an extremely inefficient but highly profitable private insurance industry.

I’d suggest that Canada has a significantly better health care system than the USA, and that Canada still can do a lot to improve it’s health care system even more.