"Correlation" being the key here. All of those things are also correlated with having a good upbringing and environment, as well as nutrition in childhood, as is IQ, so IQ is basically an irrelevant reflector of environment/inheritance factors.
If Razer can fit a GTX 1060 into a 14-inch chassis, why can't Apple? There's definitely a market of users who barely unplug their laptop while doing serious work/play, but want the option of portability. Getting a gaming/video-editing desktop forces a lifestyle change if I need to take my computer somewhere or relocate. Most places I go, I can usually find a plug if I'm doing serious work. Make a laptop as thick as the 2011 MBP with a real graphics card and the same renowned build quality please. Billions of dollars and no sense; squandered on accessory watches, dongles and pads, which barely qualify as computers for anyone in the power-user user-base and devs.
https://www.youtube.com/watch?v=8wcSSLo9TIs