Not sure about everyone else but personally I don't want a headphone jack. I prefer the slimmer phone and increased battery that is only possible once it is removed.
Related - I'm a huge fan of Airpods and only ever want to use my wired headphones with my laptop
I don't know which uses more power, wired or wireless headphones. If the wireless ones use more, idk if the additional volume gained by removing the jack makes up for that, and if so by how much.
All I know is when I want to pass the aux to a newer iPhone, I need a stupid dongle now, which funny enough doesn't work with the old one. And either phone's battery will last all day regardless.
Related - I'm a huge fan of Airpods and only ever want to use my wired headphones with my laptop