I have gone too far in the headphone hobby and have exited the nice middle zone where the headphone jack has value. It can’t power my headphones and my phone has no systemwide EQ so there would be no point anyway.
Some people in the headphones sub talked about using qudelix 5k to power it if you wanted mobile but at that point the jack becomes useful only for charging while listening (admittedly useful!). I don’t really think compromise free mobile listening works though, if you have good wired headphones they are fairly likely to be open back already. For those people, a midrange priced Bluetooth Focal Bathys is probably as good as investment as any other closed back for mobile.
Hence why I believe the headphone jack is for those in the middle of the pack: they have closed back wired headphones that are good enough to not want to use Bluetooth, but not headphones too difficult to power or a strong preference for EQ. Which is a ton of people to be fair. I only commented here cause you said “people who dislike the headphone jack must not have good wired headphones,” but I have several and don’t need a headphone jack in my phone. I’m aware that those in my position are a very small portion of the population and agree with most of what you said, just wanted to provide a different perspective.
Oh also, if you’re using an adapter for 1/4” to 1/8”, may as well just use a USB-C or lightning adapter. 1/4 or 2.5mm balanced and a shitload of power would actually make a phone jack useful for my case though!