There are no "new" materials in the 787, and the engines were developed by GE and RR under their own financial risk. They fit on the A330Neo and A350 just fine, too.
The now mostly-forgotten Raytheon Premier light business jet was the most relevant pioneer of all-composite commercial aviation structures[0] and the 787 is basically a scale-up of those principles, with a wound-barrel fuselage.
It's really the engines and the high-aspect ratio wing that make the 787 more efficient than the previous generation of airliners. All the other fluff is just marketing.
[0] and even that was decades later than all-composite home-builts, and the Learfan, Beech Starship, Avtek-400 and whole buch of others... plus of course Airbus have been using composite structural components since the late 1970s.