The real trick is to:
1) Travel at those speeds using close to the same per-seat fuel usage as conventional airliners, and
2) Design the aircraft so the sonic boom is deflected upwards, so you can travel supersonic over populated land.
The ultimate downfall of the Concorde was the incredibly high fuel usage combined with the inability to fly supersonic over land. Thus only a few routes (NY to London, NY to Paris) were possible, and only profitable with $6,000 per passenger tickets.
LA to Sydney or Tokyo would have worked great but I don’t think it had the range to do it.
“Design the aircraft so the sonic boom is deflected upwards, so you can travel supersonic over populated land”
Over 30,00 feet the boom is not really noticeable so over-land Mach is no problem. . .