I was watching him in practice. He did a ton of quad axel attempts. He didn't come close on any of them, and he did not stand up on any of them. He chose to go for it in the long program anyway, came closer, but fell and missed the next jump. It may have cost him a medal. But, I think he knew that the odds were very long and made the choice to go for it anyway. He has two Olympic gold medals. He decided that taking a long shot to land the first quad axel was worth the risk of not medaling. Others wouldn't look at it that way. Scott Hamilton and Brian Boitano said on Olympic Ice that no coach would have taken the approach that Hanyu did, but it is Hanyu who has to be the one to prioritize his goals and make the decisions accordingly. He chose to go for the very high risk long shot.
I don't think this is about age, though already having two Olympic gold medals may have entered into his thinking. He always has been a risk taker and pushed the sport technically. He won both his Olympic golds without doing entirely clean programs. At this point in men's figure skating, given the level of difficulty and risk, it is going to be a rare occasion when we see the men at the top consistently doing clean programs in competition.