If more than 8 GB cards were affordable, then more people would move to it. The share of people with more than 8 GB has been consistently going up since the release of RTX 3060 12 GB. 3 years ago, only 5% people had 12 GB cards, now it’s up to almost 20%.
People don’t buy GPUs based solely on what is required today. They also want to run games that will release 3 years from now. So people want to have the choice to buy more VRAM.