Can that explanation in Wikipedia have something to to with it?

The DOE test cycle starts with both the block and the cooktop at room temperature: 77 °F ± 9 °F (25 °C ± 5 °C). The cooktop is then switched to maximum heating power. When the test block temperature reaches + 144 °F (+80 °C) above the initial room temperature, the cooktop power is immediately reduced to 25% ± 5% of its maximum power. After 15 minutes of operation at this lower power setting, the cooktop is turned off and the heat energy in the test block is measured.[5] Efficiency is given by the ratio between energy in the block and input (electric) energy.

https://en.wikipedia.org/wiki/Induction_cooking#Power_and_control

Maybe because they need to change the "Power Level"?

So, it is a limitation of physics?

:( I feel bad now.