I think the lad is allowed to feel grumpy.
I have a lot of time for Messi, he is a great player but he knows that he hasn’t done enough in any of his world cups to cement his position alongside the likes of Pele and his batshit crazy stumpy, druggie cheat compatriot. That has got to be tough to take. His team are not good enough to allow him to flourish and he is not Maradona enough to single-handedly take them to glory.
He may get another shot in four years time but he is at his peak now so he has to be thinking “is that the chance gone?”