There's about 6 times as many hospitals in the US as in Canada, including some of the best research hospitals in the world, so naturally those with means would seek specialized treatment in many cases. But it's just one little piece of the puzzle. What about the many Americans who travel overseas for healthcare?
There you go about time you coughed up some links. Please be my guest go to a third world country for cheap care. Unfortunately your precious big government throw's caution to that wind!
Your second link, I'd love to see what access is restricted. Nearly all restrictions in the US are because of the FDA.
Most medical tourism is for cosmetic surgery (which is elective and therefore not covered, I don't care what country or insurance plan you have, generally not covered). I don't need that, I'll stay in the States, thanks.
https://www.roswellpark.org/become-patient/international-pat...
https://www.cancercenter.com/become-a-patient/international-...
https://www.browardhealth.org/pages/international-program
https://moffitt.org/
I can keep providing examples, can you do the same?