Backups. Copying photos. Sharing files. As a Mac User, you're probably well served with backups integration in Finder, as well as iCloud, AirDrop, iMessage, and friends without realising it.
Do you mean like...iTunes? Huh?
I know approximately zero people who still tether an iPhone to a desktop for any sort of backups.
Eh? I don't have an iPhone, but my mum does and she uses it fine without a Mac. Everything just syncs to iCloud, if there is some benefit to connecting it to a Mac then I'm genuinely unaware of it.