Yeah it's pretty crazy. Breaking it down into games/goals really makes it clear.8 fewer games and only 2 less goals is impressive
Messi - 27 games, 16 goals - 0.59 goals per match
Mbappe - 15 games, 14 goals - 0.93 goals per match
Christiano Ronaldo - 23 games, 8 goals - 0.35 goals per match
I will say, Messi is much more of a facilitator than Mbappe, so this is not to slight Messi at all. Still the GOAT and if I'm building a team, I take prime Messi over prime Mbappe any day (particularly when you consider their contributions on the club level). But yeah, Mbappe is very likely going to end his career as the most prolific World Cup scorer of all-time, since he easily has at least 2 more left in him after this one, and a third one does not seem ridiculous.