Now this is things get interesting. As I said earlier, Roger gave his hat to Shanks believing that he was the one to solve the history and fulfill the promise, because he himself was going to die soon. As you know, Roger lasted longer than he thought and actually solved the history which meansShanks knows about the Void Century and Raftel’s location. Roger didn’t have enough time to wage war on the WG but shouldn’t Shanks who knows everything and is good at making friends try to fulfill the promise by now? Instead, he made no such attempt and passed the straw hat on to Luffy. Don’t you find that strange?