Binaural doesn’t translate well to speakers. (And it’s slightly flawed in that it still doesn’t model your specific head/ears so without significant wizzardry it won’t be 100%)

But yes, as more and more music is listened to through headphones, I’m kind of wondering this as well…

There are a lot going on with stuff like Atmos though, and virtual studio simulations for mixing in headphones, so we might see interesting things in the future.

Re repriduction of different kinds of music I think the challenge is exactly the same. The challenge is to reproduce a signal with flat frequency response, correct transient and phase response, with low distorsion. As long as you do that, you reproduce every kind of music well. There may be tradeoffs that ate more important in some kinds of music. Soundstage/positioning perhaps being more important than sub bass in jazz/chamber music but (perhaps) not in EDM for instance. But I still think the challenge is the same. Have a good enough system and everything will sound good on it. Or be correctly reproduced atleast, which may not be what sounds the best, but that’s a whole other can of worms.

That can of worms may also be part of it, because, we might for the most part not actually want the recorded music to sound like the real thing, we want larger than life. Have an anecdote from a former colleague who's worked a lot on recording classical music for radio and TV. He had this story where he worked on an audiophile symphonic recording. They used a small set of really high quality microphones, set up as a blumlein pair as main source + some more microphones to capture and be able to adjust tonal balance, width and room in the final result. Apart from slight corrective EQ, they weren't supposed to process the sound at all, it should be all natural. Compression or artificial reverb were strictly prohibited. They did several different mixes with different mic balances, but the producer weren't satisfied and still thought it sounded unnatural. So, without telling anyone, they sent the mix through a Manley VariMU compressor, just compressing a few dB:s at most. That's the version that got released...