Last year, Aymeric Laporte played 33 league games, the most of any City center back, but this year, he's only played 4 of 18. Manuel Akanji and Nathan Ake were both brought in as backup options, but both have played more minutes than 2020/21 EPL Player of the Year, Ruben Dias, who has had his injury issues and has only played 12 of 18 games.
So now you see the difference between Haaland's and Ronaldo's goals. One's goal-scoring impact has helped the team score more goals than without, while the other's impact led to the team scoring 16 less.
I hope you now have the context to analyze this conversation from the correct lens. And if you have friends who are still in the dark, please educate them.