5 ways more VRAM doesn't always mean more FPS
More VRAM, by itself, won't boost your FPS if you have other bottlenecks on your PC

The outrage against GPUs with insufficient VRAM is intensifying, as it should, but gamers should also remember that a larger framebuffer doesn't magically mean improved performance. While more VRAM is necessary for unpacking high-res textures and the graphical info involved in rendering ray tracing effects, a bigger VRAM number by itself won't do much if your GPU or other components are otherwise limited.