Maybe somebody succeeds with a delta-wing design, but the highest-profit configuration will still be to make the seats as cheap and terrible as possible.
If BWBs become a thing, maybe the value of cabin space will decrease to the point where paying for a business class - or even premium economy - seat for long-haul travel is attractive for more people.
I did some Googling and apparently the base price ratio for business class to economy class is about 3.6 to 1. Some of that is all the other frippery - lounge access, priority baggage, better food, more personal service etc. etc. So at a rough guess providing just the bigger seat would attract a premium of maybe 3x economy class.
At the moment, New York-London with United is about $600 and business maybe $1800-$2000 (so perhaps a little bit under the expected premium, but in the ballpark). For most people, an extra $1400 is a big ask.
But imagine a world where the economy flight is $200 and business class $700. I suspect a lot more people would choose business class in those circumstances.