I have had a smartphone since 1997 so that's 20 years. Before that I had a PDA, phone and datacard.
For nearly every year the usual problem has been first battery life, 2nd has been storage.
As what you could do with smartphones has increased they moved from gimmick through convenience to an essential item particularly for travel (duh, mobile!).
I currently carry two phones either/or depends on the trip. I bike commute so for me on a bike it is a small cheap phone I can hold in one hand, and for that I use a $99 Moto G4 Play but it can crawl if I tax it. In other situations I use a OnePlus2 where I need performance, but it doesn't last as long on battery. When I'm spending weeks on the move from home I have both so I have a spare and use both. These two phones I have with ample storage done differently, one has SD 64GB card, the other 64Gb built-in.
I have touched Apple phones and spoken with their owners but in my opinion it's hyped overpriced.
Typed on my OnePlus2, heading off for 3 days trip, with Pixel C tablet, Powercore 26800, Powerport2, I'm with others so not carrying spare phone.
The whole travel and portable technology has changed a lot. I'm heading into high altitude cold for a worm trip and can work and be online whether near mains or not in a 16L small backpack which fits anywhere.