Rain shouldn't really affect your smartphone, unless it's poorly built. My Nexus 7 fell into a stream of water, getting completely submerged while turned on, and it didn't even shut off. Opening it up revealed it was completely dry, despite the case being snapped on.
Friends have had similar experiences with their Moto G, a Wiko and a cheap non-branded tablet.
Yeah it's surprising how well built are phones nowadays. I was running/cycling with a Nexus phone which I exchanged yearly and there never were any issues. Then when I got a Garmin FR110, I went for a Sandisk Clip MP3 player, who was dead in one month due humidity/wet conditions. Bought a cheapo Android phone who will stay on Kitkat forever and sticking with that instead.
If I would use my phone to play music the battery would be dead by noon.
If it rains while im on a run, I only risk 120€ not 500-900€.
Not to mention that an ipod is WAY lighter (12.5-31g) compared to a smartphone (130g). Which makes it less iritating when you carry it in your pocket.