Boom is a YC company building a modern, supersonic passenger airliner: https://boomsupersonic.com/
This is a realtor talk right here. Selling limitations as benefits.
I'd actually wager a significant portion of the population would correctly say Airbus, but for the wrong reasons - it's the only French aerospace company they can think of.
I did a straw poll among some friends and got a lot of "I don't know what that is. Do you mean the grape?"
Who names a rocket "Fireball"?
The airplane talk, let alone an SST, is pretty much all about the engine. So, with none of them putting an engine on the table, whatever else they do is, honestly speaking, pointless.
Be sceptical.
Even the best military engines today will barely work for the role.
They need around 20t of dry thrust at speeds at speeds around Mach 1.7-2.0, and big enough fan for takeoff at the same time.
I think efforts like these suffer from serious disconnect at best, or some criminal lack of ethics at worst.