You're shifting the perspective of your arguments as you go here - that's generally not a very good way of making a point, and serves to show that the ground on which you are building your arguments is shaky. In one sentence you're arguing from a perspective of "gamers will need more than 10GB of VRAM, Nvidia must provide", and in the next you're arguing from a perspective of "it doesn't matter who buys the GPUs as long as they sell". See the issue? The latter perspective is in direct conflict with the former. Are you arguing from the perspective of the "common good" of gamers, or are you arguing from the perspective of Nvidia continuing to be a successful business?
I'm not shifting perspectives, you're probably overanalysing my (maybe too short) messages.
The whole point should be considered only from the viewpoint of the company, in a more or less competitive market.
I'm pretty certain that in a year or two there will be more games, requiring more than 10k of VRAM in certain situations, but I think if AMD comes out with a competitive option for the 2080 (with a more reasonable amount of memory), reviews will point out this problem, let's say, in the next 5 months. If this happens , Nvidia will have to react to remain competitive (they are very good at this).
As for what you are saying: for compute customers, any sale of a potential 20GB 3080 is a lost sale of a 3090 - those customers can always afford the next tier up if it makes sense in terms of features or performance. The compute performance difference between the 3080 and 3090 is small enough that 100% of those customers would then instead buy the 3080 20GB unless they are in the tiny niche where another 4GB actually makes a difference. For the rest, they'll just buy two 3080 20GBs.
No SLI on the 3080? Anyways, I will repeat myself, Nvidia will do this only if they have to, and AMD beats the 3080.
And again, 20GB of VRAM with no additional bandwidth or compute performance makes pretty much zero sense.
Do you mean to say that the increase from 8 to 10 GB is proportional with the compute and bandwith gap between the 2080 and the 3080? It's rather obvious that it's not. On the contrary, if you look at the proportions, the 3080 is the outlier of the lineup, it has 2x the memory bandwidth of the 3070 but only 25% more VRAM
Games won't exceed 10GB of VRAM any time soon unless their developers either don't care or are incompetent.
Older games have textures optimized for viewing at 10802p. This gen is about 4k gaming being really possible, so we'll see more detailed textures.
They will be leveraged on the consoles via streaming from the SSD, and on PCs via increasing RAM/VRAM usage.