Personally, I do actually feel that Paul George is a little overrated here. That said, there are a few reasons why I consider George better then Hayward.
1: Consistency
Over the past four seasons Paul George has averaged at least 21 points, 6 rebounds and 3 assists every single season except for 2014/15 (which doesn't count, as he only played 6 games). Over that time he's averaged between 36% - 38% from three and betweenm 86% and 91% from the free throw line in all of those years except the injury seasons. He's been considered one of the best defensive wing players in the league over that entire stretch. For almost half a decade Paul George has consistently been one of the top 5 or 6 wing players in the NBA on both ends of the court, and at 26 years of age there's no evidence to show he can't still get better. You know what to expect from George, year after year he's playing like an all-star.
Over the past four seasons, this is the first time Gordon Hayward has averaged over 20 PPG. He's never averaged 6 rebounds per game. His assist numbers have been about on par with George. His 3PT shooting has varied from 30% to 38%. His FG% has varied between 41% and 46%, His FT% have been fairly consistent. His defensive reputation has varied between "woeful" and "good". The one year that he's finally putting up star-like numbers happens to be his contract year as well. Once he gets a payday, will these numbers hold up? Nobody knows really. It's a big question mark...especially for a guy who wouldn't sign for less then a max deal, which you know will be something like ~$30M a year over the next 4-5 years.
2: Success
Paul George has carried the Pacers to more success then they probably deserve for years now. They have had very unspectacular teams, and he's carried them to the playoffs every single season expect the one where he played 6 game due to injury. He has a proven record as a leader, as a winner, as a guy who can put a team on his back.
Hayward has played 4 playoff games in his career, and they all came in his second season when he aveaged 11 PPG - so it's not like he did much to contribute to it. He's played alongside guys like Paul Millsap, Enes Kanter, Al Jefferson, Derrick Favors, Rudy Gobert, Rodney Hood - he has had reasonable talent around him. Sure, the West is tougher and I acknowledge that. But the fact remains that Hayward has never really done much to prove that he's a leader, a winner, or somebody who can be depended on every night to carry a team.
That's even before you get to the physical aspects - the athleticism, for example, is something you can't teach. George is so far superior athletically to Gordon that it's not even funny.
These are two main reasons why I rate Paul George a whole level above Hayward, and why I think almost every GM in the league probably would too.