All that wing looks like a lot of drag/fuel burn to me.
Big wings reduce fuel burn.
Lift to drag ratio plays a big part in your fuel burn. The 777X for examples requires less thrust than the 777W despite being heavier. This is because the greater span improved lift to drag ratio 17 to around 20.
Ideally you want a wing as long as possible but what stops this is weight grows exponentially with span. Carbon fibre allows for greater span with the same weight which is what made the 777X possible.
This design uses a truss brace to strengthen the wing. A very simply design allowing the wing to be much longer. The lower truss has also be designed to provide its own lift as well. This design would easily achieve a lift to drag ratio of 25 which is similar to the U-2 spy plane.
I estimate thrust requirenents would be reduced by around 30% compared to a 737 at the same flying weight.
This design could also easily fly 10,000ft higher than a 737 design reducing fuel burn by another 10+%. Fuel burn of the 77W imporoves significantly when it moves from 30,000ft to 40,000ft. This going to 50,000ft would have a similar imprivement.
Add new engines in 20 years time with a 20% fuel burn improvement and we now have a total of 30%, 10% and 20%. So the 70% number is realistic.
Engines look a bit small no?
Less thrust required. Plus the big wing will make them look smaller.