You can disapate heat into the metal chassis without a fan, and if your CPU only generates a few watts, even at 100% this doesn't cause it to overheat. This has been done with desktops that are.much more powerful, but it's also been done on the new M2 MacBook air, because the m2 CPU is quite efficient. It doesn't overheat because the case passively dissapates heat fast enough. It's also not a performance laptop.

that's because apple uses arm chips which are much more power efficient than Intel and amd's x86 chips

it mostly uses 15-20 watts or around that which is easy to dissipate than 45-50 watt Intel and amd produces which requires fan

I've heard even the most powerful m1 max chip doesn't need fan when video editing (which can go for continuous 6 hrs on battery and you don't see a performance hit when charging or on battery)