But it’s still surprising they haven’t. People would be motivated as hell if they launched GPUs with twice the amount of VRAM. It’s not as simple as just soldering some more in but still.
They sort of have. I'm using a 7900xtx, which has 24gb of vram. The next competitor would be a 4090, which would cost more than double today; granted, that would be much faster.
Technically there is also the 3090, which is more comparable price wise. I don't know about performance, though.
VRAM is supply limited enough that going bigger isn't as easy as it sounds. AMD can probably sell as much as they get their hands on, so they may as well still more GPUs, too.