In terms of aircraft sales, the 777-300ER was the big hit. Just about every major player operates some form of the triple. LH doesn't, but LX and OS do. Of course, Southwest doesn't. It's kinda like where the 767 was in the 90s (more transatlantic crossings than all other airlines combined) or the 74 in the 80s. Big, efficient at a variety of load factors, and can haul cargo without cubing out.
Not a lot of fun ten wide behind those monstrous engines, but the economics are great.