Except that that is, in fact,
literally what "realism" means.
Look it up. Or, if you don't feel like it:
link 1,
link 2,
link 3,
link 4.
In every case, when "realism" is used to refer to literary or artistic things, it is
always referring to depictions attempting, as much as possible, to display things like they actually are in real life. That's very literally the whole point of the word.
And "fantasy realism" is not a thing. The closest you'll get is either (1) the Vienna School of Fantastic Realism, where the "realism" there refers to....depicting scenes as closely as possible to what they
would be in real life, if they did in fact exist in real life, they just coincidentally don't happen to. Or (2) "magical realism", a primarily literary space where realistic environments are presented...but they also happen to contain supernatural or unphysical events, which are not treated as unusual or even all that worthy of comment by the author/artist.
In literally every case, however, "realism" as a particular branch of expressive endeavor, is about making things as similar as possible to what is actually real. Hence, I said what I said. The depiction of
religion--not deities,
religion, the practice and complexity and day-to-day living within that practice--in Eberron is worlds more realistic than that of nearly all other official D&D settings. The pseudo-Christian henotheism of nearly all D&D worlds is an
extremely unrealistic portrayal of religion, even when taking into account that gods are demonstrably very real and quite powerful in these settings. The religions do not function as social entities; they function as
gameplay components, to a degree that even I find troublesome. Not so with Eberron. Its religions actually have the shape and behavior that one would expect--and include problems, complications, contradictions, and foibles, so, so many foibles.