Right, because aircraft are going to replace all their 3.5mm jacks. And professional audio equipment is going to drop 3.5mm / 6.3mm jacks. And ATM machines - they often have 3.5mm jacks for audio interfaces for the partially sighted.
These things are going to be around for a long, long time - and have far more ubiquity than just mobile phones.
That's without taking into account there not being one standard for non-3.5 / 6.3 connectors - Apple uses lightning, some new Androids have usb-c, the majority of others are micro-USB.
The lack of a single standard that all manufacturers use is a single issue.
Plus, non-3.5mm headphones will always be more expensive than their 3.5mm counterparts - lightning connectors cost more, having dacs and other circuitry on board costs more.
Lightning / USB-C has a potential benefit for noise cancelling headphones being able to draw power from the device - I might be tempted to go that route specifically for that purpose (but there is still the issue of non-standard connectors - I'm not wedded to one particular manufacturer of phones, and I don't want to be limited by the accessories that I've bought).
Beyond that, you would be crazy to spend large amounts of money on high quality headphones (which I do) that can't be used in a wider context. I would sooner buy a 3.5mm headphone, and simply use an adaptor / external dac if it absolutely came to that.
But there is no good reason for getting rid of the standard connector - you don't need to do it for waterproofing, you don't need to do it to save money, you don't need to do it to save weight, you don't need to do it make the device thinner - hell, the devices are already more than thin enough, and many would benefit from being a little thicker with better battery life.
And it doesn't stop people using BT / lightning / usb-c headphones if they want to. It is just a move to extract more money from consumers, and to create another fake barrier to disuade them from changing manufacturers.
Except, as I said, this isn't just about a phone accessory, in the same way that we would only use floppy disks with PC/Mac, etc. They have a ubiquity across an enormous range of devices, and none of those are going to USB-C/Lightning, especially while there is no single, cheap standard.
I've already embraced wireless - I usually use a bluetooth headset when out walking listening to podcasts whilst walking. They are great. That doesn't mean that I don't recognise the limitations of bluetooth headsets - with battery life and recharge times, or that I'm willing to sacrifice a 3.5mm port for NO benefit, even if I rarely use it - because I do still need it.
You must be too young to remember that airlines have already switch their proprietary headphone jacks over the period of a decade not too long ago. In fact some older planes still have them. Now airlines are adding USB, after a brief flirtation with AC power (it too various incompatible standards). So while they are unlikely to remove the 3.5mm Jack, they will likely all add USB, with which any smart headphone will attach. Are airlines going to switch from USB-A to USBc ports? Eventually, especially is USBc becomes a standard. And eventually, just like those old proprietary "airline" headphone connectors, they will go away in favor of digital alternatives. But passengers are going to have to carry adapters just to charge their phones. And if passengers forget, chances are a friendly neighbor can accomodate, or I'm sure the airlines will be happy to rent you one, just like they always have and still do now if you leave your headphones at home.
Professional audio is a pointless example. For starters 3.5mm is not a professional audio connection. 1/4" and 1/8" TRS connectors are. 3.5mm is a consumer standard, which pro audio gear tends to accomodate along with XLR, and the other dominant standards. And that's what pro gear tends to do, accommodate every standard needed. And they have more than enough room to do it as well. They're also starting to have USB interfaces well. And one thing that's always been true with audio equipment, people always need adapters.
Next up, ATMs. ATMs will be a thing of the past in a few years as digital payment systems take off. I haven't used an ATM in years. And they are giant hulking machines that can accommodate whatever anyone needs. To the extent someone needs to actually use such an antiquated device, it will accomodate their needs. In fact there's room to add a digital and a wireless interface if anyone thinks that's necessary.
The fact that 3.5mm Jack won't necessarily be removed from equipment means nothing as far as adoption of a new standard. But retaining it simply to give those who don't want to change the option, when there are likely other considerations for consumer mobile devices, is pointless.
You have a cynical, jaded bias, just like most of those against this change, and would rather assume the worst of Apple than give them the benefit of the doubt and analyze what this change actually means. There a number of eventual benefits to customers going digital, if not immediate, and absolutely no reason to cling to the 3.5mm Jack which cannot deliver them, if the only reason to do it is that it's ubiquitous, and cheap.
I don't understand the mentality that says smaller and lighter is not an important consideration. The iPhone has maintained its battery life, or improved since it arrived. As long as they don't lower the battery life, I'm fine with that, and I'd like to keep it as small and slim as possible. If I need more battery, I'll add a battery case. For those who want a thicker case, they can do the same thing. Why should I be penalized for those who can make their phones as thick as they want any time they want, with as much power as they want with add on accessories?
You make a lot of claims about Apple not needing to make the decisions they may make about dropping the headphone jack, but in the end, you don't know jack. Nobody knows what exactly Apple plans to introduce to the iPhone next or what their internal space needs are to accomodate it. It's all rumors. Moreover you're basing your opinion about what wireless tech Apple will introduce with the next iPhone, entirely on your previous experience with Bluetooth, this despite the fact they just released BT 5, which you know nothing about.
But I totally agree with you it would pointless to buy expensive headphones that can't be used in a wider context. That's why you buy digital headphones that can be used with anything, just by swapping the cable. Maybe even one that has multiple connectors built-in. For all the hand waving going on, this is likely to not be a real inconvenience to anyone, with at least one casual survey confirming that. I've yet to see a survey that shows a demonstrable majority opposed to this change. Just a bunch of people on tech boards, who generally complain about the loss of legacy connectors they're currently using.
