MOVED: Steam Deck low textures override

Yeah, it is a physical hardware limitation on the deck.

To elaborate more. In order to remove that limitation, you need to have a dedicated/discreet GPU with a minimum of 4GB VRAM all to itself.

Minimum spec is 8GB RAM and 2GB dedicated VRAM.
Recommended spec, which removes that limitation, is 16GB RAM and 4GB dedicated VRAM.

Sure the Steam deck has 16GB RAM. However it is shared ram. It gets used for both the system and the APU. So not only do you not have a dedicated GPU with its own separate dedicated VRAM, you don't have a dedicated GPU either. It is an APU built onto the CPU chipset. So by basic hardware standards, the Steam Deck does not even meet the minimum hardware requirements for the game.

It will probably be better once 1.0 comes out. Then your Steam Deck will likely have a version with the same configuration/limitations as the Series X and PS5.