I think supplements as a category are simultaneously broadly over and underrated.
People are promised the world by companies, then underwhelmed by real world results, then chase the next big thing on a regular basis anyway.
Very few supplements will do much of anything reaching statistical significance if you start taking them, and then literally continue on your exact same trek without deviation.
If you are taking a supplement that increases power output. You need to decide that you’re going to add 5…10…whatever…pounds to each heavy lift set, and then do it.
If you are taking a supplement that increases time to failure. You need to decide that you’re going to do more reps than you’re used to.
If you’re taking a supplement that increases recovery but don’t increase workload than whoop dee doo, you’re less sore the next day but you’re not actually taking advantage of that increased recovery to make more gains over time.
If you aren’t taking advantage of that extra capacity, you might be less sore afterwards, or feel like you’ve recovered faster, but you aren’t really going to see much difference in gains.
People take a new supplement, than go to the gym, and follow the same 3x12 at x/y/z weights trajectory they were already going to do, and then wonder why their gains are slow.
Get a spotter. Work to failure. Actually push your workload. And that is where the benefits of effective supplements are seen.
This impact is demonstrated very clearly in the (limited) number of well-controlled studies out there. Studies that use actual dietary control, studies that use actual workout control. The placebo groups and the supplement groups in those studies wildly outperform uncontrolled studies, and the difference between placebo and supplement groups is much more likely to reach statistical significance in those studies.