To be fair, a fan takes away from potential heatsink space and eliminates contact from heatsink to shell. A fan based cooling system can actually be worse than a fanless setup... especially if they're the Macbooks with constrained intakes. (virtually all of them)

https://forums.macrumors.com/threads/macbook-pro-17-my-cooli...

https://hackaday.com/2017/12/14/cncd-macbook-breathes-easy/

https://www.ifixit.com/News/6882/why-i-drilled-holes-in-my-m...