I don't mean to underestimate Atalanta, but when compared to other clubs in the Champions League, there are several clubs above them in terms of strength, including Arsenal in my opinion which is slightly better than Atalanta. However, they are still a club to be reckoned with and anyone who faces them must be careful.
Last season in the Europa League was a real example when they managed to beat the strongest candidate to become champions. Almost everyone was not on their side, but in the match they were actually able to become winners, including beating a club that was unbeaten in all competitions last season.
On the other hand, the difference is that because the Champions League is different from the Europa League, here they will get more pressure, so they must be ready for that by improving their mentality.
This is not the first time that Atalanta is will be playing in the Champions league. They have been in the competition in previous times and they fully understand what it takes play in the Champions league. In my opinion any team that manage to win the europa league can cope with the demands of the Champions league. Atalanta did very well in the europa league last season, they even performed far better than some clubs that participated in the Champions league. The only difference is that here they will be playing with more bigger clubs that boast of more squad dept and experienced managers. But I believe that Atalanta can survive the group stages and even make it as far as the knock out stages. Atlanta is not the least club in the Champions league, I know it will be difficult for them to win the Champions league, but they are also a strong side that can win clubs with same ranking as them. Sometimes they can even win bigger clubs too. They did it against Liverpool last season, under Jurgen Klopp.
True! Atalanta is already a team with experience in UCL and they even had great runs in the last decade and like you said above , this team mentality fully understands what it takes to actually play an UCL game and what it takes to win an UCL game.
I also think that Gian Piero Gasperini really changed the ADN of this team and since his arrival , Atalanta improved every year to become a top football team in both Europe but also in Serie A where they seems to be top 4 almost every year now.
In my opinion, Atlanta performance in the European League cannot be underestimated considering their achievements last season when they managed to win the European League for the first time in the club's history, but to be honest, I don't see that Atlanta will be the team that surprises us this season in the Champions League, not that I mean underestimate them but so far Atlanta's biggest achievement in the Champions League was only reaching the quarter-finals in 2019/2020 and that year was the first year that Atlanta played in the Champions League, so I think to say they are very experienced in the Champions League is of course wrong because of their participation Only 3 times in the Champions League in history.
Atalanta was a bottom team in the previous Serie A, but they were consistently able to be in the top 4 positions, so we should praise them as a team that in the last few seasons has been very consistent in being in the European competition zone so far, but we also You shouldn't expect too much from them in the Champions League because the atmosphere of the Champions League and Serie A is very different.