Outside of SLI, you can 'double the VRAM' in certain non-gaming applications, and some games that support multi-GPU through DX12 (Though this is quite rare, put all the burden on the developer)
Sure if you want more graphics power these days you have to look toward buying a better GPU. But there was a time when that wasn't the case and there was
Outside of SLI, you can 'double the VRAM' in certain non-gaming applications, and some games that support multi-GPU through DX12 (Though this is quite rare, put all the burden on the developer)