I think Madrid keep become the favorite team as the winner although leave by Toni Kroos next season but arriving Kylian Mbappe will make Madrid attacking line more aggressive with Vinicius Jr, Rodrygo, Jude Bellingham will be good partner for Mbappe.
I don't think huge problem for Real Madrid and their tactician Carlo Ancelotti after leaving by Toni Kroos, they have many top qualities midfielder will back up Toni Kroos position with Camavinga or Carlo Ancelotti moving down Valverde become holding midfielder. I believe Carlo Ancelotti manage well with his smart tactician moving some players from their original position such as did with Rodrygo as winger moving him as false nine or central forward.
In essence, Real Madrid still has many young players in every line and as such, of course Real Madrid will still be fine even though Kroos has retired and Modric has left. Of course, it doesn't make it difficult for Ancelotti to maintain good performance for Real Madrid, because Real Madrid is also still very good at carrying out regeneration, so there is no doubt for Real Madrid for next season.
But indeed, because Real Madrid has many young players who have at least the same position in the attack line, this will result in them being placed in other positions in order to strengthen Real Madrid's attack line. I think it won't be a problem, because at least these young players will still get good playing minutes and won't just be on the bench.