Because iPhone sales aren't dropping because of the headphone jack and people seem to be enjoying Bluetooth headphones given how popular those are.
As for sales dropping, smartphone sales do drop. Or at least, the upgrade cycles are becoming longer. It is mostly because phones are becoming "good enough" for many years, but the removal of the headphone jack may have played a tiny part.
Admittedly, far more expensive. But wired headphones come with iPhones
they're only "doing it" with their own limited hardware combinations. the experience of pairing any random bluetooth devices even in ios is still mediocre overall.
[1] Cricut Air but then it also has trouble talking Bluetooth reliably to my Windows 10 desktop; I'm not blaming this on iOS just yet.
Because I bought the Sony 1000MX3 and its pairing at least with one device is much faster and more reliable than Airpods. It definitely is worse with multiple devices however.
In my personal experience they have decent sound, pair reasonably easily (through NFC and "normally"), and the connection is pretty stable.
Pairing partner were various Samsung Galaxies.
I recommend Sony BT headphones.
That said, I also use the 3.5mm jack regularly :-)
I have several BT devices, and I never know how they're going to work in the next month, when the next software update is going to be applied.
Ubuntu's BT stack (bluez) is well-known to be trash, however, I was surprised when my Android phone BT's stability took a dip after some "security" updates.
I think the heart of the problem lies here. It's the fact that we have to pay solid attention to the UI when we make these changes- and we have to care about the UX. This thread is focusing on bluetooth, but I had this experience when iOS updated their text-message interface. I guess there are more buttons to push now, but what is missing is being able to attach a photo that you've already taken by tapping an icon next to the text entry. Now that only opens a camera, and you have to go to the "lower level" to attach a pic that you've already taken.
No big deal, right? Now, if you were going to change your UI and add an icon that signifies attaching a photo, what would your icon look like? If you were going to hunt for one, what would you expect to look for? They use something that doesn't call to mind photographs in my mind[1]. It took me an annoying amount of time to figure out this change because I was in one of those situations I was trying to get the picture off quickly.
In fact, this whole trend of replacing labels with icon and having no mouseover fallback is a huge time-sink. Now, that might have been Apple's icon for a long time, but the fact is I never needed to know that before. It was in a place that was obvious (next to a camera or something, I really don't remember what it changed from).
I mean, am I seriously supposed to know what this means[2]?
[1] http://cdn.osxdaily.com/wp-content/uploads/2015/04/photos-ap....
[2] https://boilingpointdev.files.wordpress.com/2013/08/game-cen...
Apple used to use Samba, but had to drop it in MacOS 10.7 when Samba switched from GPLv2 to GPLv3. I can't really fault them for making a change based on licensing concerns.