That is such a strange question. Vale Tudo is synonymous with MMA. UFC is a brand of MMA events, products, etc. UFC is currently the most recognizable and succe

That is such a strange question. Vale Tudo is synonymous with MMA. UFC is a brand of MMA events, products, etc. UFC is currently the most recognizable and successful MMA promotion in the world. I guess to answer your question, the UFC is a big deal because they were the first promotion to bring MMA to the global audience and have been 1000x more successful doing so than anyone else before their existence. This is little different than asking why the NBA is a big deal, why the NHL is a big deal, etc when basketball, hockey, etc existed for many years before those leagues formed.