Bottom. Phones go in pockets top down so you don’t have to readjust your grip. If it’s on top, now whatever’s plugged in is holding up the phone. The only real benefit for a top port is the ability to have stereo bottom speakers without space constraint worries.
Honestly it doesn’t really matter to me. Depending on whether it’s on the top or bottom I’ll just put my phone in my pocket to make it point upward when I use it. I tend to use Bluetooth anyway most of the time, so the headphone jack is mostly there as backup and for connecting other audio devices at parties etc.
I’d say bottom because I’d rather not have the cord coming towards me, rather than away, when I’m using the phone. Also it seems more ergonomic for me to put my phone in my pocket with the top pointed down rather than up.
My Xperia 10 III has it up top. Damaged more than one cable by just jamming it in my pocket upside-down then realising the cable’s getting smushed up. Note to self: Get headphones with 90 degree cable connectors
I try Bluetooth every couple of years but it still sucks so much.
It amazes me how after 30 years and a million spec improvements, it still fails so often for me at basic things. Connecting consistently (and quickly), pairing consistently (and quickly), etc.
I know it’s partly just some terrible, cheap implementations of Bluetooth that are to blame, but I don’t care. I plug in headphones, they work. That’s what I want headphones to do. Not have to worry about charging, and being dirt simple are an added bonus.