What will happen to Serie A clubs in the 2024/25 season, clubs competing in European competitions such as UCL, UEL, and UECL, they are unable to divide their focus and concentration well. If they perform well in the domestic league, they fail in European competitions, and vice versa if they perform well in European competitions, when playing in the domestic league they perform quite badly. Likewise with what happened to Napoli this season, they were able to win the Scudetto because they did not play in any European competitions, so they could always focus their concentration and energy on every match in Serie A.
However, even so, I hope that for next season, the teams playing in European competitions, they can divide their focus well and get quite good results too. It's been a long time since I saw a single Serie A club lift a European trophy, especially in the Champions League.
This is why even the biggest clubs have trouble making treble. Real Madrid once won 3 UCL in a row, 3! which is near impossible, I do not remember if anyone has ever done that. You know what happened? They didn't get the treble in any of them, they never do. So, we need to remember that getting the treble is incredibly hard, hell winning the league and the cup itself is usually pretty hard, not impossible but even that doesn't happen every year, so add UCL on top of that and it would be near impossible.
You do not need just a perfect team, but you also need the perfect team cohesion to make sure bench players are perfect and always ready too. That way, whenever a player is injured, booked, tired, the bench could take over and look like it did not change a thing and they are still great.