Why couldn’t they build it with a jack? Due to the thickness?

I’m typing this out on my iPhone 6 (which I will keep until it disintegrates because of its headphone jack) and it is plenty thin. I think only Apple themselves are obsessed with thin devices.

Heh. No. It's about DRM. Incrementalisim is powerful. They just pretend it's not.

The 6 is the thinnest of them, 6S and onwards are all thicker

Thinness and waterproofing are the two things I've heard that lead to removing the jack.

Neither seems insurmountable, but if you want to try and remove as many obstacles as possible in the search of those two things then the headphone jack is apparently one of the simpler ones.

Speakers, camera lens, physical buttons, charging, and data transfer are the remaining ones I can think of, and many of those have already been replaced in some models.

Samsung's been shipping waterproof (or at least water-resistant) headphone-jacked phones for years now.

Yeah, I mean it's not like they need to allow air to pass to the interior of the phone. All you need is a couple of exposed metal tabs, no different than the USB/lightning port.

Exactly, I think there are solutions for more or less everything I listed, or solutions could be found if necessary.

I think the headphone jack is a very practical component of the phone, and miss it regularly, but removing it does remove a few limitations on the designer.

At some point, in perhaps the not too distant future, I wouldn't be surprised if phones had been reduced down to look like not much more than a piece of glass. Maybe even a piece of flexible glass!

That's definitely been the trend for a while now, and things like edge to edge screens and wireless charging move us further in that direction. Thankfully neither of those seem to have necessitated the removal of some other function. There have been other casualties other on this path to simplification, such as the removal of the physical home button, but I don't think any which leave as big a gap as the headphone jack.

That would definitely be cool, we see them fairly often in modern scifi films/shows too nowadays.

Can't be thinness because the thinnest iphone ever is the 6s, which has a headphone jack and it can't be waterproofing because android makers seem to do waterproof phones with jacks just fine some of them even thinner than iphones too.

Nooo. Don't take my headphone port from my MBP!

In my home office, I have it wired to my simple mixer and amp with which two other computers also connect to. And from that split into my speakers and a pair of headset.

All non-digital and no USB involved with other things that can go wrong. I am no Hi-Fi buff, I just like one volume and power button when I need to silence or amp things.

Whilst commuting on the train I also use the headphone jack, even though I also have a Bluetooth headset, but it is limited to two sources which are already used up by my iPad and phone.

I don't want to yet again swear internally whilst standing on a busy tube with 1000 other people with Bluetooth devices, and having to reset the pairing on my iPad/iPhone.

Ps. I have an old phone with a 3.5mm jack, but I never use it. I use audio on my phone only when commuting or walking and then use Bluetooth. But my old iPad and MBP are stationary so I only use 3.5mm devices with them.