I switched to a Samsung because Apple was failing to actually continue to add anything substantial to the newer iPhone versions. At the time the Galaxy S3 was an upgrade but the latest iPhone was not. A lot of the "new features" added to each iphone iteration are actually software, not hardware, and work fine on the previous version.
Of course, like Apple, all smartphone manufacturers seem to have stagnated lately. The S5 over the S3 has... what, a heartbeat sensor? Why the **** would I even want that on my phone? Minor camera upgrade, still using the same tiny-ass lens that is on every cell phone. At some point, shoving more pixels into the sensor doesn't help much. What do you even add to a phone at this point? Higher resolution display? 1080p on a ~5 inch display is already pretty ridiculous pixel density, and you'll still be hamstrung by battery limitations.
I know, I have an idea. How about one of you smartphone manufacturers comes up with a phone that actually has decent audio quality for phone calls?