“Unearned irony" is the deployment of a dominant narrative line that is the nominal subject of the story, while at the same time winking and whispering and nudging the reader that it's ,like, so weird. This eye-rolling irony dominates the book , and avoids the work needed to make real irony work, which is that real irony is the result of several situations in the narrative being developed, over time short or long, that result in nuanced epiphany where a character in the story is at odds with the "real world" he inhabits.
The power resides in the not knowing when the effect takes place: the point is that you're not supposed to see the irony approaching, best shown in The Recognitions by William Gaddis, or The Horse's Mouth by Joyce Carey. The effects here are worked for artfully. Eggers stops just short of announcing that he's being ironic.
A magician who shows how their tricks are done perhaps ought not to be a magician: maybe an editor. Or a literary critic. Now that would be ironic. For editors, it is precisely the job of an editor to make manuscripts into books, to eliminate the fat, to blue pencil digressions and areas of receding interest and, believe, send pages back for rewrite. The tendency is to let manuscripts, "experimental" or otherwise, get sent to the press without editorial oversight. It's a waste of perfectly good forest.
Wisdom needn't be the censor that kicks in after a certain age, but it can have the effect of giving one a sense of how an interesting life can be told in an interesting way, ironic or otherwise. Best of all, though, an acquired wisdom ought to avail one with a self-editing instinct and to realize the difference telling a story and committing coffee talk to paper.