Age have nothing to do with Ronaldo , he is still very active . The reason why maybe much clubs are not interested in buying him is because of the high amount of money to sign in him. This season Ronaldo have not played football in a full match compare to last season that is why he has not done much.
Ronaldo said he was going to retire at the age of 40 that was from his past interview with Piers Morgan. He is the most ambitious footballer ever in history of football. He has said he will love to play with his son in professional football. And also, he has a lot of records to protect due to the activeness of Lionel Messi. He thinks he still has a lot of years left in professional football. I do not see him going to Saudi Arabia. And I am very sure he will sign for a top team in Europe. Possibly, Napoli.
Ronaldo is still very vibrant and can fit into any team that is doing well.Lets be realistic here,When Ronaldo came to Manchester United,the team was not in form at all,and at that time,it looked like Ronaldo was their messiah in almost all the matches,if he doesn't score,no other player will be able to score.It got to a point that the player was tired,he could not score those goals again because there was no one to really assist him,it was then that Man u came up against him to say he is not performing well.
Ronaldo is still very good despite the fact that he is of age,he can still deliver in a team that is good.