You're onto something but that's not entirely true for all games. There's plenty of vintage games, made before DirectX standardized everything into the late 90s, that don't work well under wine because back in their day, they would try to bypass windows by "hacking" their way to the hardware via unsupported APIs and hooks, to squeeze every bit of performance from the hardware, and also because every hardware vendor back then from graphics to sound shipped their own APIs.