You do realize that what you are describing is an edge and most users don't have a use case for 5 connections including a "test kit" right?
If a phone would have to cater to all these edge cases we'd still have serial ports on them.
Wired headphones cater for these edge cases.
As I say, I can live with a dongle for 3.5mm or serial (despite it being a regression), it's just another straw.
The certainty and simplicity of an audio jack is not valueless though, no matter how many people on HN say it is.
> The certainty and simplicity of an audio jack is not valueless though
Nobody is saying that audio jacks are valueless in general, just that it's reasonable for a mass market device where it has value for a small % of people to not have it.
A £50 mixer takes these inputs (almost all from 3.5mm sources) and brings them all together via a reliable tactile interface.
On the road of course I only tend to have to choose between 2 sources, so perhaps beats can approach the utility of a 3.5mm audio cable.