Ronaldo age is not a big problem for clubs interested in signing him in this summer's transfer window. The proof of Ronaldo age is not debatable because he can still make a big contribution to the team as last season he was the top scorer in the Manchester United squad. even his arrival can increase the club income from the sales of merchandise and other accessories. Bayern may be the best choice for Ronaldo besides PSG because these two leagues have not been tried by Ronaldo during his career.
Ronaldo is still playing well and his performance is even better than many young players, not only players at his age. However, it is untrue to say ageing is not a big issue for Ronaldo. Now he is able to score less goals than a few seasons ago, you can not order him to score 40 or 50 goals like 5 years ago. In addition, you can not order Ronaldo to contribute a lot for defense at his age.
In fact, at the age of 38, he is still in demand by many clubs. In fact, many big clubs want to bring Cristiano Ronaldo from Manchester United. It proves that Ronaldo's quality is still maintained even though he is old.
As you said, that Ronaldo is the top goalscorer at Manchester United, it's one of the proofs that he can still compete.
It is because he has very excellent skills to score goals and a lot of goals. It's hard to say no with a player who can score 30 goals in each season. However, any club uses Ronaldo has to know that he has little contribution in key passes, assists as well as lack of defense contribution. They have to require other users to cover that weakness of Ronaldo. It's not easy in modern football when all players have to be responsible for defense.
But even so until now there is still no certainty which team will sign Ronaldo, many teams are being linked with Ronaldo now but it's just a rumour. So yes, Ronaldo does have its own charm but unfortunately, his old age and too high a salary make teams who want to sign him will certainly consider him again. But if these teams really need a player who has a good influence to motivate the team even more so to help him win the Champions League title next season, then Ronaldo is the right player but if they consider for the long term then Ronaldo is not the right choice.
Big clubs have better choices than Ronaldo. It's better if they choose Kane, Son, Salah, Mane, Mbappe, Haaland as they are younger players and can play for them in more seasons. With Ronaldo, they can not have plan that is longer than 2 or 3 seasons. Let's see Ibrahimovic. He played very well 3 and 2 seasons ago but in the past season, almost no contribution for AC Milan. Players at the age of Ronaldo can end their career anytime with serious injury.