"Word War One was poorly coordinated by outdated generals" is a bit of a myth, and several previous answers have discussed this.

In Why does it seem that virtually all sides in WW1 were cursed with some of the dumbest generals in history?, u/Rob-With-One-B and follow-up responses from u/Klesk_vs_Xaero and u/Kovechnik81 discusses overall competence and acumen of generals who fought for both the Entente and Central Powers.

Usually when this topic comes up, many focus on British General Douglas Haig. Answers to Did any of the high-level officers in WW1 express any remorse over the lives lost due to their incompetence?, by u/Rob-With-One-B and How accurate is "Blackadder Goes Forth"? by u/NMW focus specifically on Haig, and the "Lions Led By Donkeys" narrative that perpetuated history and popular culture following WWI.