It's easy to explain from a business point of view.
Yeah but ain't the customer part of the market model?
Coz there are ZERO chance in hell that I can spend 800 for a GPU, even if I get that it makes more sense for the manufacturer.
So you tell me what AMD should prioritize making.
The GPU that me and 90% of the people can buy, a ~250-300$ GPU, pretty please with 12-15GB of RAM as it is cheap.
In the GPU market AMD is both lazy and stupid: they just try to undercut NVIDIA a bit, they should understand that they don't have a product as good as RTX and focus to provide decent low price GPUs with a lot of RAM in the 200-400$ range.
If someone has 500 to spend they could as well spend 650 and buy NVIDIA, those on a budget on the other hand would buy AMD if they had proposed a 12-16gb good rastering option on the cheap.
Arms system usually lack the standardization, common interfaces and customizability of x86 on the desktop, those are good in a vertical produced product like Apple does not in a open ecosystem like PC.
Then you got price and retrocombability (or lack of thereof) of software running on Windows. PC user don't care for the latest super efficient CPU if they can buy last year or two years old x86 for 1/3 of the price with enough power for their standard stuff.
I don't care for an 16 hours laptop that costs 1.6k when I can get a decent 8h ryzen laptop for 500 , I'll buy an external battery in case.