The US government is held captive by the groups profiting, politically by leveraging the electoral college (or lack of a popular vote) and skewed population representation in the senate, also massive voter suppression by gerrymandering, and facilitating a docile populous by means of broad education inequality, and lastly steering opinion via mass media controlled by those groups.

>Is there a reason America doesn't follow the rest of the world and ...

It's completely impossible, and this is why (the "follow the rest of the world" part). America simply cannot follow the rest of the world. If America doesn't invent something first, and someone else does it first, America *will not* adopt it, ever, no matter how much sense it makes.

There is far more profit to be made and so it will not happen.