You should be asking yourself why the US would buy a supersonic military aircraft when they've spent the last 70 years moving AWAY from higher speeds because it doesn't provide any value.
Why would you spend a single dollar on making your launch platform go a little bit faster when the thing you are launching goes faster than Mach 4? And that was true in the 80s.
Power output is important but top speed is not a priority. The B1 Program was cut partially because you could just buy 100 stealthy cruise missiles for the price of one B1 bomber which the Air Force did not think was more survivable than a B52. In the 80s.
Every country has built slower planes entirely because higher sustained top speed just means a more expensive engine, more fuel usage, and more frequent maintenance.
Boom insists they will somehow magically overcome all of those problems.
I'm not saying that supersonic aircraft is particularly useful. I'm saying that it's not widely presented in the USAF.
I'd say that manned military aircraft should generally be on decline, and manned fighter aircraft, tenfold so. The future belongs to drones that can withstand 30G, and have the "brain" more evenly distributed within the craft to increase survivability, and which can carry extra 1000 lb of payload because they have no human + cockpit + ejector seat + life support system on board.
F-22 is a marvel, and can fly supersonic for much longer, but its cost is exorbitant, and it's not even produced any more.
F-35 is more economical but it literally can fly supersonic for a minute or two with the currently installed engines.