No, it wasn't.

Automatic weapons were coming on line at pretty much the same time armies were going with fully rifles barrel breach loaders.

The Gatling gun is only not a machinegun by virtue of whacky legal definitions, and was around when most militaries had just upgraded their muzzle loaders. WW 1 was the era of the belt fed machinegun. Take a crew served belt fed MG on a tripod firing 30-06 or 8mm Mauser and you can rain hell down on incoming troops at 2000 yards.

People talk about how the WW 2 German army with their bolt action rifles weren't really outgunned because individual rifle fire was secondary to the MG. That was true of the USA too just not quite to the same degree.

Even look at Afghanistan today. A dozen fighting men can be engaging the enemy with 5.56 weapons but once you bring that M240 into the fight shit changes in a big way