The opinions of shouty people on another forum don't necessarily make the majority view, but with the ongoing list of technically poor AAA PC releases this year the question of how much VRAM is enough is being hyper focused on now. For high end gaming, whatever that means, it does feel like 8GB is moving down to entry level. IMO I don't feel 12GB would be lacking for the next couple of years or so for a upper-mid range card like 4070. You probably do want 16GB at the top end.
The 3060 situation came about because nvidia decided 8GB was the minimum needed for that tier GPU, but due to their chosen memory bus that meant it could only be provided by going to 12GB. There is a question if 8GB is enough now, and 16GB may have been added as an option. The much rumoured 3080 20GB never happened. Let's see what happens. I haven't followed closely but it is also rumoured that AMD lower end GPUs for this gen might also be 8GB, so at 8GB nvidia wont be at a disadvantage on that metric.