no need to wait 40 years it seems that Ronaldo game yesterday was also not visible when he was young maybe his performance has decreased even the way he plays is not as good as it used to be when he was young and maybe it's because of his current age, I think even though he continued his career in football to 40 years old not sure he will get minutes to play long on the pitch at any club
If comparing with Ibrahimovic then it is very different. Looking at their way of playing is also very different. Ibrahimovic didn't put out much skill to get past opponents and he made the most of the ball finishing. Unlike Ronaldo, in his youth he ran a lot and passed opponents, and at the moment it is not very noticeable because his physique does not support it. So it feels like Ibrahimovic is kind of better in old age than Ronaldo. Of course, Ronaldo should be able to model Ibrahimovic's way of playing, not moving much but having the best finishing. At the moment it is best, because improving abilities will already not be able to, because of its age.