I live in Mexico and pay for private health insurance because I want nothing to do with the government ran health system. Don't know what makes you think it's one of the best ran in the world.
If the same issue were to come up here in the US, I would have 2 options:
1 - with current ACA insurance - pay $200 + 50% of cost = $700
2 - with no insurance - about $1200 out of pocket
Which option do you think I (and most other people) would prefer?
And the thing that makes the system one of the best in the world is that it provides care at prices that middle class people can afford and where those prices are public quickly and easily to everyone. And it does so with a relatively small cost compared to GDP.
Compare that to the expense of Canada's system or the insanity of the USA system.