Before Metal they used OpenGL, and Apple being Apple, they wanted to have their own thing. I remember way back when they were advertising OS X as UNIX... Until they got sued and had to take that down. The macOS interface is nice, but nothing revolutionary. Most of the ideas come from Steve Job's NeXT, which Apple bought on the verge of bankruptcy... along with Steve Jobs. That's how he worked his way back into his own company. Anyway, a lot of macOS mirrors Jobs design philosophy. The problem with macOS is the aging subsystem, the Mach microkernel, poor scheduler performance, and a stupid driver system that doesn't allow anyone to make a driver for macOS unless Apple approves it. And they're about to close macOS to the Hackintosh community, a community that served Apple well for over a decade because they found most of the bugs and security vulnerabilities. Apple wants to move further away from big computers, workstations so on. They used to make OS X servers at one point. So macOS is more and more morphed into a embedded OS, that also happens to run on Intel. For how long? We don't know. The bottom line is that Apple is pursuing the luxury computing market, with less emphasis on actual performance and more focus on trends and lifestyle. And that's what macOS mirrors today.
Yeah, they are a bit like the Tesla of the computing world in many respects, or maybe Tesla is like them?
The lack of updating the GUI was mainly what I was referencing in my original comment in this thread. That's a real plus for the folks that aren't big into major changes. Apple has succeeded on that front by making the changes relatively subtle. There have been progressive updates, but none of them are huge jumps like Microsoft tends to make.
On the "switch to embedded front", yes, they are working more and more on turning MacOS into what we see on iPhones and iPads, the iOS shift. The phasing out of Intel hardware (which I'm running on all my Macs except my ancient G-series stuff) will likely have me shift this box to Windows or Linux once it is sufficiently obsolete. Right now, since it still works with all my Steam games, I'll stick with it.
Pushing out the Hackintosh community (that's where I was really first introduced to Darwin, I was a FreeBSD guy at the time) is just another part of that whole shift to catering to the more embedded side of things and the "smart device" ecosystem where Intel-based systems are part of that legacy framework that they are trying to shrug-off as they push to move to platforms that run on ARM and their own CPU's.
Not to get too OT, but on the UNIX front of course that was the whole code-split between Berkeley and AT&T. The commercialization of that codebase (UNIX) vs the "keeping it free" philosophy (BSD). It spawned a ton of derivatives on both sides (DEC Alpha Unix, HP-UX, Solaris, IRIX...etc and NetBSD, OpenBSD, FreeBSD, Darwin...etc) which really ultimately helped make these competing platforms familiar and accessible. But, on the workstation front, I'd argue nobody has been as successful as Apple in gaining market share in the consumer realm.
Amusingly, a clinic that is in one of our buildings, up until a couple of years ago, was running a Mac server (rack mount). It ran PS Suite, which is one of the Telus EMR products. They were a wholly Apple org, so having an Apple server just made sense. One of the few I've seen in the wild in commercial service. Another EMR vendor used to use redundant Mac Mini's running Ubuntu as their "server" platform for clinical deployments. They had a 1U rack setup that had two Mac Mini's in it, one as the main server, the other the backup.
