dedication

 We live in interesting times.

If I wanted I could just go and buy a pro camera which allows me to shoot professional-grade videos. This however requires dedication in a sense that I would then need to focus on that one thing exclusively.

That's fine as long as you have time and motivation to do that.

In my case however, producing high quality videos is not my main priority, especially when travelling. Sure, it would be nice to have a nice, stable, 10-bit 4:2:2 vLog footage, which I could then colour-grade when back home, however, that's not my main goal (and I also don't have time for that). It would require a lot of equipment and time. Often times, when travelling, there is not much time, so it's much easier to, say, take out your phone and shoot, rather than set up entire rig, with gimbal, microphones, lenses, etc.

On the other hand, I wouldn't be happy having some poor quality footage, because then... what's the point?

So, a compromise has to be made.

Also, if I'm going to get a proper stills camera, it would make sense to also get a proper video cam as well. 

That's when iPhone comes in.