Agreed. Boom claims they will be "sustainable" because they are going to invent some kind of synthetic biofuel.
Wait, it looks like I either misremembered that claim, or they have backed away from it:
> "Overture’s fleet will be able to run on 100% sustainable aviation fuels."
https://boomsupersonic.com/sustainability
Color me skeptical. Making existing aviation more climate-friendly would be a much more worthy goal than this ridiculous supersonic vanity project.