I would have mentioned genetics. But when I started, I started with some bag seed photos. Wasn't the best quality on Earth, but I got some chonkers. Then I started looking around for reasonably priced seeds from people that had a decent reputation. And got really good results. As I learned more, then I started expanding more into the hype train. And getting even better results in some cases. So as people mentioned it's a combo of things. But I do always come back to light.
So I'm always hesitant to say "genetics" because I don't want to imply that someone newer go out and drop hundreds of $$$ on whatever is being hyped. I don't mean "hyped" necessarily as a negative either. Mephisto is fantastic for instance, but hyped, and deservedly so. There are a number of reputable breeders out there with good genetics at lower cost. I would recommend some of them as you learn what works. Dunno if that makes sense. But...when I began my journey with autos, I was looking more for $5-$8 seeds rather than $15 seeds. Wasn't because I was cheap, I just didn't want to frustrate myself with uber high expectations. I know SO many people who drop $50 on a pack of Night Owl in the beginning and are so deflated when they're not pulling a pound off the plant.
I pretty much top, lst, defoliate, minor lollipop everything. But the reason I do that is based on...light.