Well, linux already runs perfectly fine on ARM chips, so it probably won't matter much. The real bottleneck is getting game studios to build arm releases of their code, which by itself is easy in normal circumstances but they often have third party code that doesn't have ports or are abandoned or hidden behind NDA's (networking code, sound processing, custom tooling etc). So ARM and Linux are not the blocking factor at all and I'm willing to bet most of the engineers working on game engines have ported them to linux/arm for fun already, they just can't release for various reasons above.
So if anything, we need to push more game studios to use open source dependencies which will make porting easier.
Linux is terrible on ARM, I don't agree that it runs perfectly fine at all. Try loading Ubuntu onto a Snapdragon laptop for example. It works but lots of issues eg sound, webcam quality, etc
GNU/Linux has trouble, but thanks to Android (and ChromeOS), we know Linux itself specifically on ARM does actually work. Freeing those drivers is another matter, unfortunately.
Webcam firmware & colour grading & programming is a black art btw.
Those are specific firmwares for those devices that are either closed-source binary blobs, open-source hackjobs/reverse engineered attempts, or just plain missing firmwares. The fault is not on Linux but rather on Qualcomm not releasing things for that specific SoC. Some SoC's have better support than others. ARM cpu's themselves works perfectly fine on linux.
Intel has closed things down: some wifi and webcam firmwares are poop and a massive pain to get working on newer chips (if at all). Their wifi firmwares also don't respect certain kernel overrides (which is why I replaced my Intel Wifi 7 chip with a mediatek Wifi 6 one). Blame is 100% on intel and not linux. Broadcom is also pretty bad at being a team player in this regard.
I basically recommend everyone to stick with AMD chipset & GPU's where possible, because they have mainline kernel support nailed down 95% of the time.
Again, ARM works fine, their extra firmwares for extra devices on SoC's are to blame if you struggle.