There's a difference between "better than Concorde", which isn't exactly a high point of efficiency, and defying the laws of physics to make supersonic flights so cheap they can operate flights between origins and destinations that aren't commercially viable to fly direct at the moment (like your trip to Brazil) in sufficient comfort to attract people that don't do long haul at the moment

The barrier to most people not to visiting places that are very far away isn't "flights are 40% longer than ideal". 40% cheaper flights would open up the world more, but this is a step in the opposite direction