I think we desperately need to answer the question of why GLP-1 agonists are so effective, and particularly whether it's counteracting something in the environment that has been acting to reduce GLP-1 (or other glucagon-related pathway) activity without us realizing it. The obesity data practically screams that something happened in North America ca. 1980 that messed up our metabolisms, and it may have spread to Europe after a delay. Unfortunately, it seems like one of those things where there are various people with pet theories and little substantial effort to get to the ground truth. Perhaps the inevitable search for "me-too drugs" will uncover something.