All aspects are important, but genetics are genetics... If the genetics are not there to yield the weight it will never happen even if everything else is optimized. Out of all things I'd take A++ genetics over the best of anything else. If I gave you a low yielding 10% thc strain with mid level grow environments (newts/lights/temps) you will never get it to yield much more and get THC much above 10% no matter how good the lights, newts or temps are.
getting a decent grow room with top of the line newts is so easy it's silly... getting a high yielding high thc or CBD strain is not easy. yes you can get 18-22% stuff that yields well but I'm not talking about that because once again, a perfepuct room and lights will hardly make a difference unless the mid level grower was killing their crops somehow.