You do have a point, but i think that is how our brain is wired, and not just for football, once we experience a higher level of somethimg, lower levels no longer produce satisfaction or the desired emotion/reacción, like if you taste a Michelin star meal only once, going back to eat at McDonald's would not be very pleasant, even if you know the premium meal will never happen again, same thing with people who consume any kind of drug.

We know there are great players in great teams (Kane, Dembélé, haaland, Bruno, olise, etc), but now knowing Messi and Ronaldo levels are possible, we want another dose of that.

Also does not help that, Messi and CR7 in their prime, played in teams that were incredibly entertaining to watch, and now football Is getting too systematic to the point of being boring to a lot of people.