I don't think any team is afraid or worried about Arsenal's presence and in fact other strong teams are wary of teams full of history who have always been regular champions of the league. Maybe Arsenal is very scary for any team in the same group but after that they are nothing more than a team that can be knocked out easily.
This is funny but you said the fact, Arsenal are still lacking in experience to challenge stronger teams and most teams frequently play in the Champions League have more threat than Arsenal but in a few years they would also get to that level if they are able to maintain their performance and qualify for the champions league every year.
Since the era of Arsene Wenger to Mikel Arteta, it has taken countless times for them to reach that level and in the end they still couldn't do anything. Perhaps the highest achievement that Arsenal can be proud of was in 2006 when they made it to the final round of the Champions League but unfortunately at that time they had to face an overpowered Barcelona team which we know any team would lose if they faced it.
Maybe Arsenal's realistic target is to continue to qualify for the Champions League every season and at least they won't embarrass their fans. I think that's enough because even in the domestic league they have to face challenges that are almost as tough and even now they haven't been able to feel the title they lost a long time ago. So Arsenal has a lot of work to do.