Am I wrong thinking that after a few weeks of cutting the leaves, the root will become gigantic and will keep producing leaves at a faster rate? The only way to get rid of dandelions is to pull the ever growing root from the ground.
Tertill whacks weeds using a spinning string trimmer, which cuts the weed off near the ground. Because Tertill lives in your garden and goes looking for weeds every day, weeds are always small when the robot finds them. A whacked weed may sprout again, but sprouting takes energy stored in the seed or root. By coming back every day, Tertill never lets a weed develop the leaves it needs to replenish this energy, so eventually the weed gives up and dies.