Not a great analogy imho. You’re comparing power output vs useful power input. TDP is about thermal envelope, which is a factor of the power input but not the

Not a great analogy imho. You’re comparing power output vs useful power input. TDP is about thermal envelope, which is a factor of the power input but not the useful output. Perf/watt would be a better point for your analogy. But TDP doesn’t care about perf/watt. It just cares about energy output regardless of how much is useful.