Fair, I hadn't considered the intercontinental ballistic passenger missile approach.
The supersonic plane would have advantages over the rocket approach though. Rockers require long, inconvenient transfers to offshore launch facilities. (But would have the selling point of a microgravity transit.)
The terminal deceleration on an ICBM trajectory would be lethal. Ballistic passenger transport at global distances has to be almost orbital so the entry is sufficiently shallow.