feel free to quote one single widely regarded global quality rating, or when you're ready to admit they do not exist, come crawling back here ... but hey seeing as "hundreds have been done" it should be easy to quote some ...
nearest attempt is the world steak challenge, its method is terribly flawed in that it focuses on specific restaurants and specific butchers etc, there is no "country rating" though people tend to add up all the medals by country and declare the one with the most the winner ... a upmarket steakhouse in Antarctica could fly in the best Japanese cut and prepare it to impress judges and the win would go to Antarctica
one would also need to enter the competition first before having any representation, many beef producing countries don't enter at all