Baldur’s Gate 3 developer Larian Studios shared a statement to explain why the game isn’t launching on Xbox alongside PlayStation 5 and PC.
The issue is technical, as the studio has problems getting split-screen co-op to work the same on Xbox Series S and X.
Source: N4G PC Baldur's Gate 3 Team Explains Why the Game Isn't Launching on Xbox Consoles Alongside PS5 and PC