Standalone Dolphin has Direct3D support but the core doesn't!

Standalone Dolphin has Direct3D support. RetroArch also has Direct3D support. RetroArch has an Dolphin core. But the libretro core doesn’t support Direct3D, what’s the logic? What prevents it from supporting Direct3D? All I hear is sound! The video is just an white screen!

EDIT: RetroArch - Create a Direct3D 11/12 backend for the D3D driver [$160] Now I know why…