Letsrun distorts perception because it's distance-heavy, but to be the face, he'll have to transcend the sport to gain mainstream recognition like Usain Bolt and, recently, Eliud Kipchoge.
Jakob Ingebrigtsen is not the face of track, and I don't mean that maliciously. His wasn't even the biggest news story out of Paris, and his WBP was cut out of the TV window for most of the world. Much of the international pre-meet buzz was on Noah Lyles and, especially, Sydney McLaughlin-Levrone.
I'd say he's not even the biggest name out of Norway - that would be Karsten Warholm whose name packs a bigger punch and draws more attention in athletics circles.
To the OP, you have to define the term so people aren't talking about two different things.
Traditionally (in America) "the face of..." is the person who both epitomizes and represents a group or organization. As in "For years Neil deGrasse Tyson has been the face of astrophysics world-wide." If a normal person has only heard of one astrophysicist, it is him. He isn't even a full-time scientist but he is the face of that community.
So what do you mean in your original post? What about Jakob were you talking about? Looks? PRs? Records? Name-recognition? Likeability? Dominance?