The 16-inch Apple MacBook Pro with M1 Max SoC has been tested on multiple benchmarks while in high-power mode. The 2021 laptop managed to churn out some slightly higher scores in a couple of tests, but on the surface the overall result appeared to be underwhelming. However, it's possible there was a flaw in the MacBook Pro 16 testing.
https://www.notebookcheck.net/Apple-MacBook-Pro-16-with-M1-Max-high-power-mode-benchmark-battery-ostensibly-ends-not-with-a-bang-but-a-whimper.576080.0.html
My reaction to the title was that there's something wrong with the laptop's battery. For example that you can not do anything intensive when it's almost empty. Therefore the battery ends not with a bang but a whimper.
It has already been established that "high power mode" only changes how the laptop uses the fans, it doesn't change the SoC maximum clocks speeds.
So unless you are in a situation where it would start to thermal-throttle, you won't see much of an improvement. That is why Apple mentions that it could be useful when editing 8K videos.
If anything this shows that the chip and the cooling system are quite efficient on most circumstances.