The mental aspect changes as well as they get older, meaning it could simply be changes to personal life. He has a couple children now and those little things start to affect the mentality needed to compete. Could affect the willingness to sacrifice for training, time away from home, or simply the ability to suffer. All these things add up, if only in the tiniest manner. It can affect risk-taking. It may not be worth it anymore as priorities change. I'm not saying Roglic can't overcome any of this, but he is human. That said, I think Roglic could still win the Tour under the right circumstances. It may require him transfer some of his bad luck to other guys, but he's still at that level he can win it.