Rocks are okay, contributes to aeration but not all rocks are created equal for this role. If they're porous rocks, awesome. Bark and twigs contribute a nice supply of nitrogen with their decomposition. What you're dismissing as worse might actually be improvements.
Miracle Grow rocked the ag world by coming up with a soil blend that seemingly never comes up short on nitrogen for the plant. Unfortunately, that makes it not ideal for cannabis where there is very low demand during flower and it's just in there interfering and contributing EC that is useless to the plant, competing with other nutes, and fostering a soil environment that is less ideal for producing resins and rich terpenes.