I don't know why older players like Luka Modric and KDB are still accepted by Serie A teams right now, but that's not a big deal as long as they still believe in their abilities.
Because in Serie A, quality and experience are valued. The league is not as strong as it used to be, and it’s not as focused on speed as before, but it’s still a quality competition.
The guy is a world class player and every team wants him to join them except maybe some top teams which try to pick younger talents for the long term.
Real Madrid is another story for real with its attitude to kick old players from the team regardless from their performance because they work for long term performance and results, regardless from players name and contributions to the team.