I suppose it's a matter of acceptable approximations and cost. If only 2% of players have a high quality surround sound system, and only half of those have a good ear, then you really only have 1% of users who can tell the difference between raytraced audio and the heuristic "hacks" that sound engineers have spent decades developing. So I don't know if audio raytracing will become mainstream in games anytime soon. But I also suppose that if one engine does it, others will follow suit.

Same thing with this Unreal 5 demo. Most users would not be able to tell the difference between rendering 16B vs 8B triangles per frame.