I agree with you, I believe Arsenal are a good team but they are not yet the team to compete in the Champions League and win the trophy. They might not fare too well against tough opposition in the Champions League. To do well in the Champions League tournament or to secure the final, the best performance is required and we may not be seeing that best performance from Arsenal right now. We could see PSG with Manchester City Real Madrid Bayern Munich in the semi-finals of the Champions League.
Don't be too quick to judge and now all the teams have reached the quarterfinals. Arsenal does not have a satisfactory reputation and it has been a long time since they reached the quarter-finals. I have another view and the Gunners look like they will explode in this tournament until they reach the final. Bayern Munich is indeed very strong, in the past they even created a unique score in two legs against Arsenal with the same number, namely 5-1 with a win for Munich. But this season the condition of the German team is starting to decline a little so Arsenal has the opportunity to beat them.