Benchmarketing. It has hardware support for video codecs so it can play video efficiently in particular even though people traditionally think of that as something processor intensive.
The question is, what's the battery life when you're doing kernel compiles or GPGPU.
That feels about right to me too. I don't know if I'm usually just doing more computationally intensive stuff than most with my 16" M1 Pro, but I think the only way I could get anywhere near the advertised numbers is if I basically just had Safari open and the display on half brightness.
And not to beat the already long dead horse any more, but toss in some electron apps running in the background, I probably average somewhere around ~7 hours or so. I'm not convinced the 10+ hour lifetime is possible if you've got stuff like Discord/Slack/VS Code open.
But in terms of when I am doing truly evil things to it, I am surprised it lasts as long as it does, be it max CPU compiling or all of this morning when I was toying around with stable diffusion, it gets around ~4 hours or so.
The question is, what's the battery life when you're doing kernel compiles or GPGPU.