They are also well-established in certain markets like video and music production. And using their own silicon gives them some nice features like unified memory and power efficiency (and some not-so-nice features like lower system memory limits and non-expandability.) Apple also has some experience with AI, and hardware acceleration, so perhaps they will weather (or surf) the AI wave.

Apple abandoned both intel and Nvidia (not to mention AMD/ATI) which is interesting. Apple seems to be vertically integrated like IBM or SGI - but better at differentiation and at locking in new customers.

Apple seems particularly good at differentiated product design; their devices often just look better than the competition and seem to offer a better user experience.

(That being said, SGI's designs look pretty cool too.)

Every Mac is a Unix workstation these days. I work on a Macbook Pro and spend an inordinate amount of time running Unixy stuff in the terminal.