For me, this question - The Nile Is Better at Everything - isn't really related to the Super Skill/Attribute thing. Those are definitely a thing, but while I remember arguing against it once, I've come to think a lot of their problems are smoothed out by the fact that they're considered permanent increases and therefor change your XP costs. It *does* still make them very game-able over time, and I still see serious issues around that when people are creating high-XP characters later in the game (when they can actually decide to max out a skill and an attribute and then buy both of those within their first few Perks), but... well, yeah, we are seeing more Attribute-boosting Perks in other Realms, too, that work the same way. And while someone from the Nile can pick any Attribute, where it's looking like the other Realms will be offering on or two, most characters only care about one or two anyway.. and a Living Land character could boost both their Strength and Spirit through Perks. And of course, there are other cool options. Like, Recall Spirit is pretty good, but even a Nile Priest with Super Spirit and Super Faith still can't spam rez like a dedicated Light hero from Aysle. (OK, that's still not that easy, but I do believe it is still the easiest resurrection we have, and I hope it stays that way. Of all the Realms, Aysle's basis has a strong precedent for the revolving door of death. Except maybe the Living Land... with its wildly high Spirit and things like, for example, the Law of Life, it seems like a good place to bring someone back. I don't remember if it actually has that or not, now, though.)
But I DO think it's a thing, and the point is that it's, like, everything. Pan-Pacifica is the realm for martial arts, but Nile has Pulp Martial Artists. Aysle is the magic realm, but Nile has Pulp Sorcery. You want a kludgy parasitic prosthetic that boosts your strength? Super Strength with a couple limitations can honestly describe that better than Occultech. Caught between that and being Cyberware's annoying little cousin leaves me seriously still in the dark about what you guys can do to make Occultech interesting. Speaking of which, high tech gadgets should be the CyberPapacy's thing, with Pan-Pacifica second, but Weird Science does everything they can do, often better.
Wherever another Realm should be better at something because they have, like, half again Nile's Axiom, the Nile's answer is basically, "Ah, yes, but we have duct tape." Duct tape tech, duct tape magic, duct tape miracles, duct tape martial arts, even duct tape psionics. And since every one of those is or can be a Pulp Power of some sort (and this is where Super Skill really jumps in. Pulp Sorcery may not be directly a Pulp Power itself, but you can do Super Skill: Alteration, say, and make it one), you also get Enhancements, and the Nile is the *only* place that has those.
Ultimately, when I really bear down and look at it closely, I think that's the real source of the issue: Enhancement and Limitations. They're both more powerful and more fun to play with.
Outside of other Races - which honestly don't have much that Pulp Powers can't still do - I'm very hard pressed to think of an archetype that belongs to any other Realm that can't be built in the Nile. And then, yes, probably made better, but honestly, even just equality is troublesome. Characters are supposed to come from all over the place. If there's going to be a whole group out of one Cosm, you know it's going to be the Nile. (I mean, unless it's Core Earth because you're just starting as Core Earth, but that's a game model, not a group planning decision.)
...I have two arguments against it. The first is that, while I think the effect of it may be too strong, I DO, as I've said before, really like that feel. "Yes, but we have duct tape" is exactly the attitude I want the Nile to have. I just think they should be second best at everything. I don't know if that's really an argument against the statement being true, though.
The second argument feels weaker to me, and it is that, of course, we haven't seen all the Cosm books yet. Nile is next, so we're seeing bits of it and that's where all the attention is. The Living Land is hard to make the comparisons with, because it has always been the "most different" Realm anyway. It probably does have some concepts that would be hard to create in the Nile, but it also leans hard on the "Race card" (so to speak) to do that. As we've noted, quite possibly Pan-Pacifica will have things for Martial Arts that the Nile can't copy, and the same may be true for other Realms. I just think from what we have seen, it's going to be really hard to do that while still also not falling into power creep.