Note the “all” in the example binds to “across”, not “McD’s”. “All McD’s” - quite precise; literally all the McD’s. “McD’s all across the country” - a much lo

Note the “all” in the example binds to “across”, not “McD’s”. “All McD’s” - quite precise; literally all the McD’s. “McD’s all across the country” - a much looser group, implies various McD’s spanning roughly coast to coast (hence “all across the country”), but not necessarily including the westernmost and easternmost McD’s - just a decent distribution of west-to-east, perhaps with no giant gaps (like missing the whole Midwest).