rest of the world considers US meat unfit for human consumption

That's... Not even remotely true. The US is one of the largest food and meat exporters in the world. There's a few notable cases of differing regulations resulting in trade issues but for the most part those are about local industry trade protection. Like, the US doesn't forbid washing poultry in the processing plant with a dilute bleach solution, and the EU says you can't do that. Ignoring that the US primarily uses other things, that the same substance is mandated for use by the EU for certain classes of seafood and vegetable, and that nearly every food service establishment on the planet uses it to clean nearly everything, where it's mandated for use by the EU, and documented as entirely harmless by their advisory health officials.
But it does result in the EU buying poultry for moderately higher prices from member nations.

Fast food is better outside the US because the chains are less established as options, so they need to try harder.