These drugs are not quite as new as often reported. Byetta has been around since 2005 and Victoza since 2010. The difference is that the latest iteration of GLP-1 meds are more effective, and we've discovered they can help with a lot more than just Type 2 Diabetes.
My mom was on Victoza (she has T2D). Ozempic is better for her, and more effective, both at managing her weight and her diabetes. Her A1C has gone down from over 11% (!!!!) to 6.7%.
So yeah, sure, we need more studies on long-term effects. But these aren't drug classes that have only been around since they got popular in 2020. They've been around a lot longer than that.
Moreover: we know well the drawbacks of long-term diabetes and/or obesity. It doesn't end well, on average.