Bushings give the chain less lateral flexibility and therefore work best with a straight chainline, but, given a good chainline, I don't know what role they play in efficiency and wear rate compared to a narrower bushingless configuration. However, 1/8" inch chainrings and cogs are thicker and for that reason they will obviously wear more slowly. However, as far as I can tell, 1/8" chains wear at basically the same rate as a 3/32" chain.

There is also debate about whether or not 1/8" chains are stronger. Strength is determined by the material and thickness of the chainparts, not chain width. At any rate, this argument is mute. Even the daintiest 10-speed chains are plenty strong.

Given two identical drivetrains that differ only in width (1/8" vs. 3/32") I can't imagine that there would be a measurable difference in efficiency that is attributable solely to the width of the chain and cogs. Because track bikes lack deraileurs, ultra-round chainrings (and cogs) are critical at the highest level of competition because of the finer level of feedback and control that constant chain tension provides. The fact that the most highly refined FG drive train components happen to be 1/8" is simply an artifact of the eccentric tendency of track cyclists to stick with the traditional 1/8" drivetrain. Most 3/32" chainrings are less perfect, either because they are not intended for professional track cyclists or because they are made for geared bikes, where roundness doesn't really matter because the deraileur compensates for imperfections in chainring roundness.