EmuDeck’s default installation of Citra includes an open-source firmware replacement (HLE - High Level Emulation). This works for about 70% of games. But for titles with aggressive anti-piracy checks or complex 3D rendering (like Metal Gear Solid 3D or Pokémon X/Y ), you will experience:
I tested five demanding games on a Steam Deck (LCD, 16GB RAM) to show the difference having the BIOS makes. nintendo 3ds bios emudeck