> that last one is the most important for long term results

Empirically untrue. GLP-1s outperform diet and exercise alone.

> it's not like you couldn't combine a GLP-1 drug with great diet and exercise

This is how it's recommended to be taken. I personally know folks who were able to start regularly exercising and eating healthily because of the head start GLP-1s gave them. (They're mostly off them now, and they're all materially lighter and healthier than they were before.)