At least for table-top RPG [AD&D is a canonical example] and sci-fi convention costuming, I don;t see this. Perhaps comic / video game / anime (which which I'm only very passingly familiar) have a sorting feature where persons who ahppen to have the 'right' basic look tend to portray characters with the same look. [This would be less of a factor in less visual media.] [Alternately, it could be that the ones one best emembers are those that look a good deal like the canonical representation while others fail to register as strongly.]
Any of these mechanisms (or a combination) could account for that perception.
Added previous names I've had on a widget in my page! Because I've had some many even I can't keep track, hopefully this helps people who knew me back in the day identify me now 😭😭 the list is as follows (more recent to oldest):
Theodoor
Lacunia
Hex-
-Moongem-
Clearshadow2020
Lmk if somehow one of you remember some I missed bc I have a feeling I missed some