What makes a hamburger or meat taste good is the gentle rearrangement of amino acids and sugars in the Maillard reaction. It may be why uncooked meat as to cooked meat is less flavorful, as the umami taste only comes about through the infinite redolent ways the molecules can arrange due to the composition of molecules in a dish. For instance, bread may experience a Maillard reaction that tastes different than carrots or meat being browned as there is a greater number of carbohydrate as to protein molecules. Quoting Washington Post, ” In nature, three substances are responsible for umami taste: glutamate (as in Parmesan cheese, soy sauce, sun-dried tomatoes and many meats), inosinate (which is found in meat and fish) and guanylate (think dried mushrooms).” The combination of any two of the aforementioned will magnify the umami taste. While it is in meat that all three are combined, it is not impossible to find cooked food that also releases similar compounds- it’s just simply what makes meat more craved.