Asking out of curiosity since you sound like someone who knows a thing or two about it. I'm not the guy that can break down the minute details in the soundstage between two pairs of cans. So maybe I'm not an audiophile, but I do appreciate good sound.
Are modern day Bluetooth codecs "good enough" assuming the headphones themselves are adequate? As far as I understand it, you hit diminishing returns with audio bit rate the higher you go. I know that I, for one, have been quite surprised with Bluetooth quality in the modern day. Different story from ten years ago, say.
Firstly I think it's generally true that audio bit rate is not going to dramatically transform
most music because most music (or audio in general) that people casually listen to won't take advantage of lossless quality. Good recordings will benefit greatly. Good recordings are rare and you have to be a dedicated audiophile to seek them out.
Modern Bluetooth codecs on Android like aptX are getting very good, Apple have an opportunity to introduce lossless audio streaming somewhere down the line (like AirPods Pro 2 are capable of with Vision Pro) but the question is: Is it worth it? If the drivers themselves are not going to do a lossless input justice, then why bother with the compute overhead (which will increase power consumption)?
Speaking of power consumption that's probably a big reason why AirPods Pro 2 are not matching the performance of similar priced IEMs. Apple have to balance overall system efficiency with sound quality, wired IEMs don't have to care about that most of the time. Apple use a lot of software EQ tricks to make the bass hit harder but they don't compare at all with a dynamic driver.
Price is another consideration. My favorite IEMs at the moment cost $1k. Many IEMs in that price range have a ton of drivers (10-12+ balanced armatures for example, or a combination of those with other driver types such as dynamic drivers or electrostatics) so that adds to the cost (along with labor because of the complicated construction). More drivers will likely mean more power so battery life takes a hit, but also the unit cost goes up. Unlike wired IEMs which can you use for many years, the moment you introduce an integrated battery that cannot easily be replaced all of a sudden these devices become disposable consumables.
The market for expensive IEMs is small, the market for disposable IEMs that have a ton of compromises across the board (in audio input quality due to bluetooth limitations and the limited shelf life issue) is even smaller. With that said, I'm in that market lol.