It's easy and cheap to get USB-C to headphone jack adaptors, so anyone who wants to use wired headphones can do so. (The Apple one is $9, and we know how they like to gouge on accessories.) I've also seen simultaneous headphone-and-charging variants for under $10.
Personally, I could never stand using wired headphones with my phone, so I wouldn't want to do it. But the option's there.