I think the poor performance of AC Milan lately says a lot about their plans of not contending for the league again this season having been dropping points that should see them close the gap between them, Juventus and inter Milan but it's unfortunate they have given up already since the gap between them and the league leaders is already 9 points. For the Atalanta team, regardless of them home advantage they showed good performance as they have more goal attempts despite not dominating Milan fully in the game but they created more scoring chances dispite the Milan team coming back to level scoreline but Atalanta still manage to break through and get the winning goal they really deserve to win and they goat the win.
It seems that Milan is not strong enough to challenge for the title this season. Previously I thought they could compete again with Inter and Juventus at the top of the standings. Atalanta dramatic victory prevented Milan from narrowing the points gap with the current leaders, and I think that Milan has no bargaining power to win the Scudetto this season. Inter and Juventus are still unstoppable, and we will only see these two teams competing closely in the future.
However, if Milan makes a move in the January transfer window, there is a possibility that they will be able to compete again, or at least Pioli squad can maintain their position in the top four of the standings until the end of the season. This defeat will more or less affect the players mentality, we know that in the future they will face Newcastle in the final match of the UCL group phase. Milan will not be lucky if it continues like this, they must have sufficient squad depth to be able to compete in the race for the Scudetto.