Chuq Von Rospach breaks down the logic behind Apple reportedly removing the headphone jack from the next iPhone:

First, how many users use the port? Think about how usage breaks down:

• Users using the supplied earbuds
• Users using bluetooth headsets or speakers
• Users using the built-in speaker
• Users using headphones or speakers via the headphone jack

What’s the mix of these? I couldn’t find concrete data, but we can make some intelligent guesses. You see Apple’s earbuds everywhere: a large percentage of users seem to be quite happy with them (I don’t know why, I find them incredibly uncomfortable, but they’re free). This implies that if/when Apple releases the new iPhone they’ll likely release it with earbuds that work without the headphone jack, and that will solve the problem for these people. What percentage of users is this? 30%? 40%?

People who listen via the built-in speakers don’t care.

People who listen via some bluetooth device also don’t care. How many of these are there? Marco Arment on one of his podcasts made a comment that his analytics show that as many as half of the listens going through Overcast are to bluetooth devices (or perhaps bluetooth/speaker; I couldn’t find it to verify).

So I expect a major point from Apple will be that for most of us, the speaker jack is already unnecessary. What percentage is that? My guess is it’s around 70%, but it’s pretty clear that well over half of the audio emitted by an iPhone is already handled without using the jack, or will be with the new Earbuds in the box with the iPhone 7.

There's been a lot of speculation on why Apple wants to remove the headphone jack, including conspiracy theories that they want to take a short-term PR hit now so next year's all-new iPhone will be all glowing reviews.

I don't buy that.

I think it's simple and exactly what Chuq breaks down. Next week, I expect Apple will give us stats that'll show us the headphone jack has been dying a slow death anyway.