The entire PC community agrees the 10 GB of the 3080 is not enough long term for 4K gaming, Nvidia are just cheap bastards.
Thats why they're about to release a 20 GB 3080 Ti for $1000 in a few months. Thats why the $1500 3090 has 24 GB. They can fuck over the customers and make them pay out the ass for a proper amount of VRAM.
Feeding a GPU with data via bandwidth is an entirely different debate then the size of the VRAM buffer a on PC vs APU RAM.
You have zero understanding of how memory is accessed by the console APU if you think it can always magically access all 10 GB at 560 GB/s every cycle. Thats not how memory interfaces work. It needs to use the entire 320 bit bus for 560 GB/s, all 20 channels in 16 bit mode. The issue is for that to happen, none of the 6 GB of RAM can be accessed (which is on the same 6 chips as 60% of the 10 GB is.) As soon as say 1 GB of the 6 GB is being accessed, that takes up some of those bus lanes and slows down the bandwidth. This is why consoles like the PS4 PS5 and One X use unified bandwidth with evenly interleaved chips of RAM. The uneven split setup of the Xboxes is a major issue.
This Xbox 1st party lead engineer programmer at fucking Id Soft agrees with me and he knows whats talking about.
Educate yourself please man for fuck's sake.