Where do you see that they are comparing "people who succeeded" in the study?
I'm not the best at reading medical studies, but it seems to me like they are taking averages over all subjects in the randomized controlled trials, not just "successful" subjects.
You can't regain weight without having lost it first.
A "fair" comparison would be to compare weight gain of people who lost weight naturally, with Ozempic users who _would have_ lost weight naturally, but it's not really possible to know which Ozempic users fall into that category.
The group average can lose weight without every member having lost weight.
The study compared "everyone who did this intervention" vs " everyone who did this other intervention". That seems perfectly fair to me, it's just answering a different question to your proposed comparison.
I'm not the best at reading medical studies, but it seems to me like they are taking averages over all subjects in the randomized controlled trials, not just "successful" subjects.