You sure about that? there are plenty of portable DAC’s out there that support IOS with a single cable from the standard apple connector converting into usb c, micro usb and mini usb.
To say it doesn’t work would be like saying the lightning connector DAC that apple sells (because fuck you we aren’t giving you a headphone jack), needs a camera connector. That is just silly.
Please don’t forget that some DAP’s (high end and low) have the ability to be connected via USB to a PC to act as an external DAC.
So those you can’t really use that argument on.
Also don’t forget DAP’s that run android. They can also be quite versatile. For example, streaming a movie from it to a TV whether you are at home or on a trip and not willing to take a bunch of hardware.
You plug your headphones/IEM’s into the android DAP, stream your movie to the TV and listen from the DAP. Yes you can make an argument against that saying something like, “well I am going to be carrying a phone anyway so why would I carry essentially another phone”. It is a somewhat niche not so niche use case. For example I carry 2 phones with me at all times. One is a work phone that I can’t have anything personal on. The second is where I take personal calls, keep my handful of mobile games, I have music on it, audio books, youtube etc etc.
Remember everything that has a large market must exist for a reason. DAP’s are a specific subset of audio that provides things that something else can’t. If something else existed in the same portable size and offered the same features, then the market would slowly shift to that thing.
Funnily enough the portable dac amp market it slowly shifting to become more DAP like. Small screens with some information, menu options with eq’s etc. They are getting closer and closer to being DAP’s. The next step would literally be incorporating a way to add storage and a way to navigate the local storage and play it. So really not that far off.
Please don’t knock a market segment if you personally don’t require it or you don’t understand why it exists.