Like GSMA themselves said in the OnePlus 5T hands-on review:
"On a positive note, there's a 3.5 mm headphone jack - we'll be advocating for those to our dying breath."
True words of wisdom......
BTW, does anyone still use the 6.3 mm "proper" headphone jack?? *Raises hand*
A simple, yet to the point answer (mine too): No 3.5mm jack, no buy.
There is nothing wrong with the 3.5 headphone Jack, it's not application that does not drain your battery quick, o. K Bluetooth ones might be good, but you end up charging two items instead just one, plus they drain the battery slot quicker, if the phones battery would be larger and last longer then consumers would not be worried about using Bluetooth headphones, using the USB socket for charging and using your headphones it might damage the socket slot quicker
I'd never buy a phone with no 3.5mm jack unless i'm absolutely forced to like i was with the non-removable batteries (And i never buy expensive phones because of that. I'll be willing to spend even less if they do this). And all these things are shoved down our throats because people don't care, they have no self-respect and are totally brainwashed to consume no matter what. Me? I'll always look at a phone as a tech gadget/tool, not a jewelry. So i'll always be looking for a phone which is less of a jewel and more of a tech gadget.