It takes a confluence of technologies and market structure to make something viable.
Concorde could not fly as anything but a very expensive subsonic aircraft over populated land, due to sonic-boom noise pollution - ruling out a lot of the marketplace. London-Africa/South Asia, for example, or Paris-Beijing. Or even NY-LA.
Flying the Pacific non-stop requires a doubling or even tripling of range to avoid refuel stops (sitting on the ground once or twice part-way, for 90 minutes or so, plus acceleration/deceleration time, defeats a lot of the speed advantage). Technology has advanced a lot, but nowhere near doubling/tripling the efficiency/range of an Olympus-type turbojet (which, counting the thrust recovery from the brilliant nacelle designs, was already amazingly efficient).
That's why regular Concorde service (and thus aircraft sales) was, practically speaking, limited to trans-Atlantic routes only.
Work is being done on shockwave/boom attentuation, which might open up far more markets. But it is still small-scale experimental.
Airbus recently proposed - on paper - a boom-defeating flight profile: rocket-assisted vertical acceleration to supersonic (boom travels sideways rather than towards the ground) combined with Mach-4.5 cruise at 104-115,000 feet (30-35km altitude attenuates the boom effects at ground level) and near-vertical descent while passing back to subsonic. Quite a roller-coaster ride!
Using liquid H2 fuel that gets it range from London-LAX at Mach 4.5 - but carrying only a dozen or so pax (hydrogen tank fills the rest of the fuselage).