I would wish for all game engines to just magically start working perfectly so that no dev would have to spend resources struggling with that again.

I would wish for voice synthesizing to be perfected so that even an indie dev could give full voiceovers to games with dozens of hours of dialogue, and that even supported players giving custom names to their characters.

I would wish for a magical auto-compiler/optimizer that any dev could run their game through to improve their code efficiency to the mothersmurfing extreme, allowing for amazing performance even on poor hardware. For some reason, this thing only works when you insert game code, not other types of code. Nobody knows why.