Boeing's just playing "keep up with Airbus."
https://techxplore.com/news/2015-08-...us-patent.html
There must be a thousand "concept planes" like these, some dating back decades (but not obviously different from Boeing's) - they usually result in nothing but an artist's impression. However, there are some small steps being taken all the time towards solving the multitudinous problems involved - e.g. experiments now in progress to reduce "sonic boom" footprints, etc.
I don't doubt that someone will get there some day - all it takes is enough cash, enough will, and enough engineering (read: more cash)