That's yet another stupid adapter you have to take with you everywhere. Even though I personally use wireless headphones, I wouldn't want to buy something new when _already_ getting a new phone or whatever.
Not willing to go wireless as I use both for music making and wireless latency and compression is unacceptable. On phones I kind of understand it but IMO the iPad Pro not having a headphone socket is not excusable, there must be a way to fit it in.