It’s worth noting that Walter White could have had cancer treatment under his insurance, he just wasn’t happy with the quality of it. (This was an important plot point — all along the road it was demonstrated that Walter
did have other options, but due to his pride and greed he didn’t take them.)
In countries with fully socialised medicine, if you’re not happy with the level of care provided you don’t even have the option of paying for better care.
In countries with fully socialised medicine, if you’re not happy with the level of care provided you don’t even have the option of paying for better care.