Even though I’m a huge fan of the GoPro, technically the iPhone, iPhone Pro, or even the iPhone SE is superior. Why? The deeper integration, and also the ability to quickly upload your videos straight from your phone.
For example, having to transfer a video files from my GoPro to my laptop or iPad Pro is very slow. However, if you shoot your videos or vlogs directly on your iPhone, you can open up a Safari browser tab at youtube.com/upload, and directly upload videos to YouTube that way.