A lot of interior decisions are the responsibility of the airline, not the manufacturer. I’m thinking of the seats, and how they are arranged.

With regard to what Boeing provides, I seem to remember that the lighting was different, the overhead bins larger, and the windows were much larger, on the 787.

And then there is what cannot be seen, but only felt: The higher pressurization/lower cabin altitude, and the humidity control.

Finally, I’m sure the In Flight Entertainment (once again provided by a subcontractor) is several generations ahead of that in the 767, given the rate of improvement in electronics.