Yes, you can throttle the CPU, but then the CPU scores in Benchmarks will be lower and that's not the case... (Benchmarks are collected from different machines). So it looks the Macs consume pretty much the same amount of power.
An easy way to verify it, is to measure the benchmark delta when on battery and when connected to an external power source. (M1 benchmarks remains almost the same)
Intel i7 9750H for example has a P2 of above 80W and only then can it break the 4Ghz barrier. Even though the processor is technically rated only 45W. At 45W it can just maintain the base clock i.e. 2.6Ghz on all cores.
M1 is much more efficient than any x86 chip on the market right now.