As LWB, says one advantage to the higher bypass ration engines is that they are much quieter, the chevrons on the tail end of the nacelle that you find on some engines like on the Dreamliner and 747-800, 737 Max make it even quieter These jet engines are a constantly evolving technology and materials science plays big part, even deeper in the engine, including the hot section, new materials and composites are being used (like composite ceramics) - even just a few % in fuel savings means a lot to airlines.
