They made a gaming system built on IOS.
This wanders a bit but I hope it explains things.
Remember, if it's a laptop or desktop it's going to use MacOs, MacOs is HORRIBLE to program for compared to Windows and even worse if you want to enable gaming codecs. Microsoft put a LOT of effort into Direct X and Nvidia and AMD into plugins to make programming much easier. It's like programming for IOS or Android, need GPS? Use an already made plugin, need bluetooth, here's another plugin. That sort of thing doesn't exist for Mac and gaming. You either end up using custom programming or open source stuff like OpenGL which all takes far more effort than just using DirectX or IOS/Android plugins. So why not just use IOS stuff? It just doesn't always work as well as people think due to screen resolution and such. A LOOOT of computing depends on balance or you end up with bottlenecks, building software to run with X requirements and expectations means sabotaging a system with y specs and vice versa. This is why while you can use an RTX 3090 with a 3rd gen Core I3, the Core I3 will actually game faster with something like a GTX 1060 because the 3090 needs so much CPU power just to help load it's buffer that it can drag down the cpu. Yep, you really can actually slow a computer by putting too big of a GPU or vice versa. The same goes for software, most know that Windows is optimized for a minimum amount of ram but many do not realize that adding more has a limit as well. You can keep adding more but the benefits to the OS itself taper off once you exceed the max cache size for Windows which scales based on the amount of ram in the system. Apply this to the ARM cpu... You program the plugins to work on a small screen, ssd and ram and now you want it to work on a big screen with a large ssd and more ram... It's just not going to scale that far without hurting one or the other.
And then then is the hardware side.
The best GPU is useless without supporting drivers, software and manufacturer support and with out that no one's going to program for it, especially when there's no customers for it... Because there's no supporting drivers, software and support. Chicken and egg syndrome. Could Apple develop this stuff? Sure, but how far behind on it are they? Who's going to buy it? It's high risk high investment and there's another big problem for Mac...
Mac is only 10% of Apple profits yet consumed something like 40-50% of their development expenses when using Intel (I forget the exact numbers but it was in their financial statement which you can find online) and I was not alone in the past to question why they hadn't sold off the Mac line yet as a result. It used to be they used Mac to drive Iphone sales which drove the app store, today Macs do not drive anything, so trying to justify that development cost was becoming more and more difficult, they were either going to ditch Mac or switch to something else to reduce costs, they chose something else. They aren't going to chase an expensive, high effort, well established market like the gaming market only to capture a small fraction of it with a product they were close to selling or killing off. I'm sure they wouldn't mind a share of it, but they won't spend a fortune trying to capture it, at least not until Mac proves itself to be more profitable than it has been.