The fastest recorded was in japan at 581 km/h. That's 361mph. This roughly works out to taking 8 hours to travel 3000 miles. I'm arguing that a 5 hour flight plus delays plus lines plus security plus checkins isn't much shorter than that. With investment in it the technology can improve and go even faster. Plus it should be more comfortable, including less fees, ability to move around, ability to carry more baggage, not having to take your shoes off to board...etc. etc.