Ideally we could also control the cooktop and at least on older electrical models it should be possible to hook into the circuitry that the knobs are attached to. Without automatic feedback loops such devices are less convenient but still enable better understanding and communication and prevent mistakes. In the salmon example, you might perfect cooking your fish, invite a couple of friends and suddenly fail because you learned to regulate the power output for a single serving, not for a more crowded pan and don't know how to adjust because you don't even know the temperature profile of your perfect fish. Of course one can learn to cook by sound, smell, heat, touch sight and taste and I value poetic recipes but that does not diminish the value of temperature controlled gear.