Question

why hitler was failed?

Answer 1

Having won spectacular victories early in the war under his supervision, Hitler considered himself a military genius. However, when the tides of war changed, Hitler blamed his Generals for not carrying out his “brilliant” orders. Causing a downward spiral of mutual mistrust, in the end, Hitler only listened to himself
He declared war on USA which was way more poewerful than Germany.
He misused technology.
He had no luck in bringing strong powers to his side.
His ideals and ways were too harsh and nobody liked them.