What was new about it was combining those features. I'm not sure what to say other than there weren't any new concepts, vs. what else was out there. They were just put together really well.
I'd argue that the form factor was novel -- no BlackBerry model of that generation had a full-size screen, for example -- but sure, I agree with your general point. That point is probably even more applicable to iPads, too. However, because, as you seem to agree, Apple did a really good job putting the whole package together, they generated hype and customers, and that in turn generated a market for the apps that would follow and ultimately the whole ecosystem we now know.
From the point of view of whether iOS is an attractive platform for developing apps today, I think some of Apple's long-standard strategy -- the emphasis on low-price apps, the 30% developer tax, the ability to kill an entire project at will -- are now starting to have the opposite effect. iOS is no longer the dominant mobile OS, and the momentum is all firmly in Android's direction for the foreseeable future too. The 30% tax and the exclusive distribution channel are big downsides for any developer, no matter how successful they are. It used to be that the sheer popularity of Apple gear, and the demographics who would buy it and then passionately advocate for it, could overcome those downsides. That's not so much the case any more, it seems.