Not sure what your point is here, but as per the other replies to this comment that just doesn’t work well for all different kinds of rice. So my completely uninformed thoughts right now are that brown rice needs a longer time with hot water to get to the point we consider cooked. The way a rice cooker works, if they all do like you’ve said, makes the water evaporate too quickly so it it doesn’t get enough time to get into the core of the rice kernels of some kinds. And I’m sure it’s too much for other kinds where you end up with overcooked, too sticky or even like porridge, rice.