This is my first time seeing this one mentioned, but I'm curious, what makes something a "real" fallacy?
It seems like it's a real mistake that people make. I guess one could categorize it as a more specific case of misunderstanding a distribution of values. (In the same vein as mean vs median, outlier skewing, assuming unimodal vs bimodal distribution, etc.)
The "realness" is determined by the signal to noise ratio. In this case I find mostly joke sites, memes, and sites trying to sell a political/social agenda using it.
The first result I see on DDG for "apex fallacy" is RationalWiki, which is a left-wing site. The definition there is "when someone evaluates a group based on the performance of best group members, not a representative sample of the group members."
I can see why that's not included in most lists of fallacies. It's just a specific example of cherry picking, a well known fallacy that is already included in the lists.
It also most likely occurs when the speaker identifies with the group whose performance they are over-estimating, and imagines that a similar level of performance can be imputed to them.
Such cases are likely the result of the ingroup half of the Ultimate Attribution Error, where positive characteristics are seen as inherent properties of members of the ingroup, but exceptional when displayed by members of the outgroup.