Only if you want to use iCloud, no? Or maybe I just wasn’t able to use that at the time because I was on hotel WiFi.
Are new iPhones really doing usb 2 over usb-c?
I don't think it was using iCloud. It would show up in iTunes (haven't used my Mac much since iTunes got split up) and I could drag files around from some applications and back it up to my local drive (in addition to the iCloud backups).