>But my BMI was like 39, and now it is ~25. My blood test results the last couple of years have been phenomenal

If you’d lost the weight without GLP-1s, your blood test results would still have been phenomenal. Most of the effect you are seeing is the result of lowered bodyfat% through calorie deficit.

now, in your case calorie deficit comes from GLP1 use but in others case it can come from sustainable dieting which is little more tricky execute properly than just injecting a drug.