I had thought you weren't much of an FR guy. Or is this about Dark Sun?
Or we could recognize it as planting a flag and being a turning point. It's not like 3e hadn't presaged (or should I say preswordsaged) this development with the Book of Nine Swords, and PF's ample 3PP has continued that trend. Having martial people who can do things that aren't strictly natural is not alien anymore. It's represented, in a lot of things.
And I don't. What he does is achievable by ordinary humans in his reality. It's just that the vast, vast majority of ordinary humans do not have the actual superpower he possesses, which is his inviolate iron will. (It doesn't hurt that he's also a genius, an Olympic-level athlete, and incredibly charismatic, of course.) Other humans COULD do what he does, and a small number (Oliver Queen/Green Arrow, Selina Kyle/Catwoman, Ben Turner/Bronze Tiger, Dick Grayson/Nightwing, Jim Harper/Guardian, Charles Szasz/The Question, Ted Kord/Blue Beetle, Ted Grant/Wildcat, Helena Bertinelli/Huntress, Sandra Wu-San/Lady Shiva, Richard Drakunovski/Dragon) do more or less the same sort of thing, with variations. Some of them are wealthy (e.g. Queen, Kyle, Grayson), some are highly intelligent (Szasz, Kord), some are Eastern or Western martial arts masters (Turner, Grant, Wu-San, Drakunovski), some are acrobats or (ex-)thieves (Kyle, Grayson, Drakunovski), etc. All are presented as being otherwise-ordinary humans with high dedication, and training that any similarly dedicated, healthy human could complete.
Potayto, potahto. You say it "doesn't exist." I say it's still absolutely there the whole time--it's just that being "mundane" doesn't mean "weak" or "limited" or "incapable" or "restricted."
That's...that's what I said though. To such folks, transcending the limits means you've ceased to be mundane. You are now supernatural. Period. Whatever you were before, you're supernatural now.
That's something I reject. I think someone can still be mundane--still only be using the tools and skills and such that a healthy, dedicated person could learn naturally--but have achieved a degree of skill with those things that surpasses what limits our feeble understanding projects onto them. "There are more things in heaven and Earth, Horatio, / Than are dreamt of in your philosophy."
That is in fact how the word "supernatural" is used in a D&D context, yes. Anything supernatural is necessarily magical. It may not be spellcasting, but it's definitely magical in some way. You can thank 3e for that; that's how [Su] powers are defined. If you're going to tell me that transcendental mundane powers are "supernatural," I cannot--ever--accept, unless we also re-define "supernatural" in a way that...includes everything natural, which kind of defeats the point.
I still maintain, however, that there is a difference between the transmundane and the supernatural. The latter is spooky-action-at-a-distance stuff. The former retains extremely relevant characteristics from its mundanity. It is still linked in some meaningful way to physical action. "Research" or "meditation" alone cannot advance it, only practice and skill development can do that (though it doesn't hurt to do your research, of course). It cannot be transferred to another in any way other than imparting a lesson and then having the student drill on those lessons. It cannot be limited by any of the things which would normally stop or forestall supernatural powers (e.g. it is completely immune to any form of "antimagic field" or "dead magic zone" or the like). Etc.