Evan got the benefit of spending the last 4 years on teams who's primary offensive threats were Wilson Chandler, Ty Lawson, Oladipo and Vuc.
While Parsons was playing next to James Harden, Dwight Howard, Dirk Nowitzki and Monta Ellis. That's a big difference in offensive talent surrounding him. And throughout his career he's been a better shooter % (not by much, but he has) wise then Evan from both 2 and 3 point.
He's also bigger, rebounds better, averages more blocks and steals and fouls less. When guys like James and Paul George are in the same conference, I would rather have him then Evan. Especially if Evan is asking for northwards of 10 million. Chandler has potential to be an all-star if he became a number two option for a team (like he has been for the past month and a half for Dallas where he is averaging over 17 points a game). Evan may get there too, but Parsons seems much closer.