Yeah, he is just not one of the best out there anymore. There are younger, more hungry, smarter managers. He is still very good but not good enough. For example, Klopp will get a lot of credit this season for managing this Liverpool squad to CL places but it won't always be recognized by a large percentage that Wenger did even better to get some of the absolute dross we had in the past to CL qualification.
He is old now, hasn't adapted enough, he needs to go after this season. He isn't doing himself or Arsenal any favours.