Offensive play always have a bigger advantage than defensive play and that's why I feel PSG have the bigger edge to win it but another thing to consider in this game is that the game is a final and not just your ordinary fixtures so they will be lots of strong emotions and will power by the both teams so anything is possible and the atmosphere and the fans too will play an additional role because there are so many things that could happen with the fans cheering on their teams.
I also believe that attacking play gives a better chance of winning. But it must be admitted that Arsenal has a very strong defense.
In my opinion, there will be two scenarios:
1. Arsenal scores first and locks up their defense for the rest of the match, plus they counterattack. Result: 1-0 to Arsenal.
2. PSG scores first, Arsenal has to go on the offensive, and then PSG will finish the job with a two more goals. Result 3-0 to PSG. (Maybe 3-1 to PSG)
The second scenario is more likely in my opinion.