As I said, I don't really get the multiple leagues argument. Like I don't see why it matters unless you don't think La Liga is a good league.
The major tournament thing is complete silliness though. Messi loses multiple finals on penalties and loses the World Cup because no one on his team can finish, but that's a stick to beat him with because Ronaldo got injured in the first half of a final and had his team finish the job. Nah not for me.
My thing is always that Messi has simultaneously been the best goal scorer and creator in the world. No one else has ever done that. It's absurd that it was possible and he maintained it for a long time. Maradona was the best creator, Ronaldo the best goal scorer, but neither ever did both I don't think.