I personally love having extra storage that I can upgrade to whenever I want on a mobile device. Allows me to have things like all my music and text documents on a separate device so I don't have to worry about most of my internal storage being taken up by these files (mostly music). Local music files are also pretty important to me because I don't always like being connected to the Internet just to listen to my favorite songs.

Also, there isn't a single online cloud storage solution that I know of that I trust. I'd set myself up my own, but I trust myself even less for things like that. Last thing I want is either me setting one up and getting my files deleted by random script kiddies finding a way in or for a pre-existing cloud storage provider to suddenly delete my files because they're updating the service so people on lower tiers get less storage.

With headphones, I personally just love the ability to listen at any point without having to worry whether the headphones I'm using need charged. I personally don't love the idea of getting a little dongle to connect to my phone just for plugging in wired headphones because that's just another thing I could easily lose. Similar reason to why I hate short cords in general: easier for me to lose, as has happened plenty of times in the past.