I spent 6 months backpacking around South and Southeast Asia (which is wayy less developed than the rest of Asia), and I debated beforehand whether or not to bring my laptop.
HOWEVER, once I got there, I realized internet access is in no way an issue, as there are internet cafes EVERYWHERE (with varying degrees of connectivity, but what do you expect in rural Nepal?) and they offer incredibly cheap internet, usually between $0.15 and $0.50 an hour... which adds up to much cheaper than an iPhone would be, and is soo worth it to not have to carry the weight of a laptop in your backpack. There was certainly wifi in some of the bigger cities, so an iPhone would definitely make sense if you're planning on not heading into the rural communities, where you're not likely to find that.
Plus, you'll spend more time appreciating the exciting new world around you and less time focused on a little screen