Apple sales for Mac are much smaller numbers compared to consoles, they change generations more quickly and amount of optimization in GPU-intensive apps is nowhere close to consoles.
So they might be able to compete with Intel iGPU, but that's nowhere close to AMD or Nvidia offerings.
Apple might have huge leverage on mobile with iPhone because Android graphics drivers are horrible mess, but on Windows GPU drivers are decent and building custom driver stack sounds like too much.
Apple's custom GPUs they use in their SoCs are arguably more effort on their part.
And PC graphics APIs abstract way less of the system than they once did
I'd be curious if Apple's non-mobile SOC roadmap emphasizes on CPU development while still allowing for eGPU setups or even some built-in integration (e.g. Mac Pro with Apple CPU and AMD GPU) initially. Maybe in 5-10 years they'll shift to focusing on the GPU front and bring out their own dedicated GPU.
https://www.techpowerup.com/gpu-specs/?architecture=GCN+1.0&...
That being said, frankly I'm amazed at what most modern mobile GPUs are capable of and for most people who are casual gamers, that level of performance will be more than enough. What Apple will bring to the table will certainly be better than that, it's already better than Intel GPUs and they can still support 3rd party GPUs if necessary.
The demo they showed of Shadow of the Tomb Raider running at 1080p looked great for a game, AND it also looked awful if you compared it to the PC version on Ultra settings.
The whole presentation struck me as a big middle finger to Intel and just Intel.
I was actually a bit surprised they would break that kind of a demo out at WWDC -- I've seen that game not running in emulation and it was beautiful. That demo wasn't.
Looking at it without context however, it demonstrated the capability of the platform to run a AAA game without developer optimization/consideration.
And it demonstrates someone could make a stylized game similar to Fortnite.
And that was released in 2018. By the time Apple put out desktop class silcon in end of 2020, surely it will be significantly scaled up?
"Apple claims the GPU in the iPad Pro is equivalent to an Xbox One S, although how they came to thise conclusion is difficult to say since we know so little about the underpinnings of the GPU." [1]
[1] https://www.anandtech.com/show/13661/the-2018-apple-ipad-pro...