He was but if your just taking their defense in the OF as a whole I mean it's really negligible. They are both almost equal in DRS (-4 and -5) URZ is better for Vaughn. ARM is better for Conforto. I wouldn't say Conforto is a clear upgrade. He's a bad defensive outfielder.
Conforto's zone rating in 2020 was 851 and 921 this year. Vaughn's was 879 this year. That's all just brutal.