Nothing you said negates the simple past experience of needing a high end GPU with equal memory to the consoles. Would you buy a high end GPU with under 8GB of VRAM in the PS4 era? The answer should be no. Therefore you shouldn't get a high end GPU with under at least 16GB in the PS5 era. Yes, we know that the consoles don't use all of it for VRAM, but you expect to play at better than console settings and even simple things like shadows or more complicated things like ray tracing require more VRAM, if ran at higher settings. It's not so complicated you guys. I bet that the 10GB 3080 will be OK for the first year or so.