Agreed. Even though Apple isn't necessarily the first to do something, it seems like the others all follow suit after they do.
Before Siri: ?
After Siri: Google Voice Search (I know this existed prior to Siri, but it was nothing like Siri before and now it is -- but better, admittedly), S-Voice.
Before retina: ?
After retina: everybody coming out with high PPI screens.
Pretty sure Apple popularised the app store too.
Even UI features like kinetic scrolling, elastic bounce back, etc. I'm not aware of any device that implemented those prior to the iPhone. I think most touchscreen phones mainly used styluses before the iPhone. Correct me if I'm wrong!
The first iPhone was the first smartphone I took any interest in, so I may be ignorant to ones that existed before it!