Re: No jack, Jack.
Add to this:
Days when my bluetooth speakers inexplicably fail to connect and I can just plug in a cable instead of trying to sort it out there and then.
Headphones with 3.5mm jack at home, at work, earbud ones I keep in my jacket, hands-free (with mic) ones that live in my backpack. I do have bluetooth over-ear ones that are handy, but hardly want to carry them round all the time, and bluetooth sports ones for running, for which the battery lasts no time at all (and which don't satisfy the basic sports requirement of not trying to escape from your ears during exercise, but I'll concede that's not bluetooth related, never hard a better sports pair than some long-destroyed Sonys that clipped around the ear).
Ability to plug phone into stuff like my guitar amplifier or one of those little amplug things.
Ability to interchange all that kit between different phones, laptops, speakers without faffing around.
Ability to listen to sound without some protocol negotiation mishap introducing repeated clicking that needs you to go through a rigmarole of unpairing and pairing devices.
There's one advantage to bluetooth from a user's point of view: you don't have to deal with cables, so no tangling and you can still use a speaker with the phone in your pocket. (Actually, there's two, I can connect to my neighbours speakers at 3am and play Lou Reed's Metal Machine Music, but that's beside the point.) Quality is not going to be better, if the stars align it might be as good (for example every item you own is Apple and all your sound sources are AAC). Sometimes that's worth it, sometimes it's not.