That's not accurate. Humans absolutely cannot smell chlorophyll in a plant. Its scientifically impossible, the threshold for olfactory detection requires concentrated amounts.
The answer to the question was posted above, and it seems to be the piece of the puzzle that young growers refuse to grasp and completely ignore: the distinction between life and death. The grass smell is from letting the plant know its injured. All energy is redirected away from fatty acid derivatives that attract humans, towards fatty acid derivatives that attract predator bugs, as the plant thinks its being eaten by bugs. Sadly this reality has reached bro science myth status, along with flushing, curing, and bone dry sticky weed. And it's all related to the same issue: people harvesting while the plant is in full photosynthesis, Npk, water, sunlight, room temperatures, stomata open, the total package that's got kids buying moisture packs to keep their incurable nitrogen-loaded lawnmower weed nice and wet so they can pretend it's dank.