I highly disagree that winning or not winning the world cup is a marker on whether you should be one of the best.
Last time i checked Messi did get to the final and he couldn't win it by himself , so his team mates as a unit came runners up, not messi alone. Is that such a bad thing? Did pele win the world cup by himself or was he surrounded by other great players, maradona as well.
If you use trophies against a player then use them to encourage praise for them. Henry won everything, best player this country has ever seen in the modern game i believe, Cannivaro great defender with cups behind him. Xavi and iniesta have all trophies as well, including world cups.
My point is are those better at football than messi? No. They are extremely good players, world class even, but they aren't as good as him, and having a world cup does not put that bench mark down.
It's all subjective at the end of the day, but winning a World Cup is something factual that you can say seperates him from the greats
That being said, I don't think anyone would dispute Cruyf as being one of the best ever and he never won the World Cup. Neither did Stanley Matthews and I'm pretty certain Portugal aren't going to be winning it during Ronaldo's career
Mardona really did win the 86 one on his own though. Literally. Both of the goals in the Quarter Final with England were soley down to him
He doesn't play in that game, England go through (To probably bottle it against Germany in the Final)