O'Reilly is one of the most overrated players in the league imo, he's good but he's not one of the top 20 NHL centres like people are saying now. His defence made him overrated. I'd even go far as to say that as of this year, I'd take Brayden Schenn over him from the same team.
And Matthews doesn't get to have Landeskog and Rantanen as his teammates. He's also in his 3rd season and you're comparing him to Mac who's in his 6th. Matthews I think is better but Mac maybe has him beat by a bit in his own zone. Either way, Matthews has shit for linemates this season, he has them on the PP but at even strength, he has Marleau who's now basically like how shit Iggy was late for us and Hyman who just gives the illusion of hustling but has little hands or Kapanen who's decent but closer to a 2nd/3rd line guy that doesn't have good playmaking skills.