Every day players, even good ones, retire. Sometimes they do it because they are tired or because they think they are no longer able to play at high levels. It depends on how they do it and if they do it for the good of the team, they remain in the hearts of the fans: for example, I respect Alessandro Del Piero who at the time went to Serie B with Juventus proving to be a true captain.
And i remeber and respect him. Always