Apart from age, there are other things that can affect Ronaldo performance, maybe the lack of playing minutes unlike last season he was always in the line-up every game but this season he rarely got the opportunity to play in the early minutes. This may have been triggered by his reaction when this summer window wanted to leave Manchester United. I don't know how disappointed Ronaldo was with the crushing defeat of Manchester City, of course he was very disappointed with this result. maybe he will be able to play until the age of 40 and maybe he will move to another club in this winter window. maybe i agree with you arsenal and manchester city are by far the strongest team winning the title this season if we look at their performance so far in the 8 matches they have played.