Headphones aren't the only devices that use headphone jacks. They can also be plugged in directly to non-portable speakers. And you can use them for high (enough) quality recording.
Plus, it's still much easier to plug in the cable than go through the pairing dance.
And the comment you replied to was talking about the usefulness of non-headphone devices that also use headphone jacks. I just don't see the relevance.
Plus, it's still much easier to plug in the cable than go through the pairing dance.