Why does 8K gaming require more VRAM?

I think the textures and geometry would have the same resolution (or is that not the case? but in 4K if you walk closer to the wall you'd want higher texture resolution as well anyway, if the graphics artists have made the assets at that resolution anyway)

8K screen resolution requires 132 megabytes of memory to store the pixels (for 32-bit color), that doesn't explain gigabytes of extra VRAM

I'd be curious to know what information I'm missing