It looks like Apple Watch isn’t there yet. Maybe an Android watch is?
Google Play Music is (AFAIK) the only media player that works on AW. However, you're unable to sync podcasts to a watch, only music (even though podcasts via GPM work on the phone). So over the last 1.5 years with 2 AW watches (Moto360 sport, Polar M600) across 2 major Wear releases, I've had to listen to music on my runs, rather than the podcasts I'd have preferred. And I take my phone on walks / hikes to listen to podcasts, when I'd prefer to leave it home.
If the apple watch supported podcasts, I'd probably switch.
Still, at least I'm able to go on runs with my music podcasts.
Edit: Changed iWatch to Apple Watch.
I really don't like carrying around a large 5.5" screen phone while running; the armband pouches are about as convenient as you can get and I appreciate them for what they are, but just having a small watch device would be far better for me (and for many I assume). Easier to waterproof so I don't have to worry about it when it rains, less to break should an accident happen (I trip, collision with cyclist, etc), lighter overall. That plus having a means of shooting off a quick message via Siri or whatever voice service to just keep track of people would be wonderful.
Do I need it? No, but boy do I want it.
Yes. If I'm exercising, I want to carry the absolute minimum. If I'm doing a lot of daily tasks, I want to carry the absolute minimum. If I can get by without something phone-sized in my pocket by wearing something watch-sized on my wrist, I'd prefer the former.
Do people really want to exercise without their phone?
Yes. That is the entire reason I bought mine... Those phones are huge. It would be like strapping a plate to my arm while I run.
Which is good because I don't use the gym benches to fiddle with my phone