From 2012-2017, Cozart ranks as the 8th best SS, by WAR, out of 58 who qualified.
http://www.fangraphs.com/leaders.aspx?pos=ss&stats=bat&lg=all&qual=y&type=8&season=2017&month=0&season1=2012&ind=0&team=0&rost=0&age=0&filter=&players=0
That's big sample size. If you go by just the 28 SSs with 2,000+ PAs, he ranks 6th out of 28.
While his .714 OPS ranks 16th out of 28, his UZR/150 ranks 4th.
http://www.fangraphs.com/leaders.aspx?pos=ss&stats=fld&lg=all&qual=y&type=1&season=2017&month=0&season1=2012&ind=0&team=0&rost=0&age=0&filter=&players=0&sort=24,d
BTW, 32 is "early 30's" not "mid 30's".