Solution for very large data sets is memory expansion cards via CXL. We aren't quite there yet on the consumer side, but nothing is stopping it at the moment. PCIe 5.0 back bone, someone would just have to build a chipset and CPU combo with support. Also allows system memory or other GPUs to be accessed in the same way (In the future you could install old GPUs with large memory pools to only use as expansion memory for another, newer, GPU)
They way I see it people upgrade their GPUs long before the memory is an issue, or they are buying mid-range cards and upgrading more regularly.
If every game required 24GB VRAM today that would be one thing. As it sits, most people are fine with 8-12GB for casual use. It is when you start upgrading your monitor and asking more of a card. Just keep in mind that you as a consumer of this website/forum represent a very narrow class of consumer that is enthusiastic enough to post about hardware rather then just buying a new one when it doesn't play the latest game.