Disappointing is the best I can say. WWI was the greatest catastrophy of the 20th century. It wrecked Europe. Before the war, Europe was the center of civilization. All the great powers were European powers. The Great Powers had colonized most of the rest of the world and ran it to suit themselves. Production of coal, iron, steel, steam railroads, steam ships, electric telegraph and telephone, airplanes and airships, electric light, and modern weapons, was all done in Europe. Scientific advances were all in Europe.
WWI wrecked all this. It destroyed the Austro-Hungarian empire, and the Ottoman empire. And it created Communist Russia, a menace that would last seventy years.
The pity of it, is no one in Europe could explain why their country was at war. The Americans, led by Wilson, asked the major combatants, the British, the French, and the Germans, what their war aims might be, thinking that if you know what everyone wanted, and you could get them to a table, you might be able to work out a deal. None of the Europeans has an answer the the question "What are your war aims?" Either they didn't know, or they feared that they would sound so petty, squabbles over colonies and the like, that revealing them would subject them to ridicule. Wilson had to create the famous 14 points as a rational, before he could get the US to join the war in 1917.
So what did the PBS show talk about? A lotta footage about US racism, and the anti German feeling whipped up by the Wilson administration. Good deal of footage on the black 15th New York regiment, little to nothing about any other American unit. You'd think the 15th New York won the war single handedly. Nothing about war production, the Navy, British and French leaders, or any other topic. Too bad, Ken Burns showed PBS how to do a war mini series years ago with the Civil War. Judging by this bit of politically correct anti-American propaganda, PBS has totally forgotten how to do things right.