If you look at Arsenal's performance in the last few games in the Champions League, and especially against FC Porto, they were a bit shaky, I believe, because of lack of experience, when in a big tournament like the UEFA Champions League. So I believe their lack of experience will cost them in this game against Bayern Munich, and Bayern Munich are not a team to be underestimated regardless of their recent performances.
It would be a mistake if any team underestimated Bayern Munich in the Champions League, because a team as big as Bayern Munich is a team that is often taken into account by many of its opponents when they play in the Champions League. And Arsenal certainly doesn't underestimate Bayern Munich in the Champions League this season because Bayern Munich's performance is also quite good in the Champions League and I think Arsenal will be a little overwhelmed to win the match when they face Bayern Munich in the Champions League.
Arsenal are one of the big Premier League teams but have never won the Champions League trophy and thus, at least Arsenal do not have a big history in the Champions League as well. But yes, because in this season Arsenal are still very consistent also in the Premier League then yes, it is expected that Arsenal can go further in the Champions League thisseason. But unfortunately, it will certainly never be easy to get good results in the Champions League because afterall, the teams that are able to qualify for the quarter-final phase and beyond are teams with good performance and at least some of them have a great history in the Champions League too.
Therefore, Arsenal's journey will still not be easy, moreover Arsenal will play against Bayern Munich in this quarter-final. Although in this season Bayern Munich failed also in the Bundesliga but yes, at least Bayern Munich also has a good mentality and it will certainly be a difficult task for Arsenal to beat Bayern Munich in this phase.