It’s about misunderstanding new technology notably machine guns or to be even more correct a military career structure and organisation which prevented people who understood new technologies and try to shake the boat to rise in ranks while putting conservative officers in control of the army.

It isn't as if there was no war for a generation. The Russo-Japanese war in 1904-5 was precisely the kind of brutal industrial conflict that foreshadowed the horrors of WWI almost to a T.

But Western powers were mostly unwilling to learn from such a distant war, and lessons learnt by junior officers who observed the carnage closely weren't taken seriously enough.