> every Windows game wrapped in a translation layer will be significantly worse
That's not wholly accurate, though. Apple Silicon has reverse-engineered drivers that do perfectly well keeping up with immediate-mode multiple-pass graphics pipelines, MoltenVK is not SOTA anymore: https://youtu.be/BbJMPfXTbbE?t=447
You're correct that tile-based deferred rendering is more efficient. That's not the issue, though. Apple can (and already does) support traditional raster APIs on the desktop, because they have to for compatibility's sake. Thousands of Mac apps will never use TBDR or Metal and will never be updated to use it. And there's no good reason to stop supporting those applications, because OpenGL runs perfectly well on Apple Silicon. The same goes for DirectX, whether you're willing to acknowledge it or not.
There are hundreds of thousands of games that do not support TBDR and will never be ported to Mac in their lifetime; and Mac owners could be playing them regardless. The only one holding them back is Apple, because they'd rather Mac owners play Genshin Impact and earn Tim a few RSUs with a gachapon pull.