The barber manual from 1960's era says the same thing.

For my beard, no matter how sharp or what type of blade, a once over is never enough.

Generally, my first pass is with the grain and then I relather for a cross-grain pass, which just means that if my beard grows down in a particular area, I shave from from left to right.

X is right though, you need to find what works best for your beard type and growth pattern. The suggestions in the barber's manual is for professionals to give their customers a good shave without the irritation because an irritated customer may not come back.