Most here will be Apple fans and rooted in the eco systems with more than just an iPhone but imo Apple doesn't need to worry about us. It's those who just have a phone and aren't rooted so can easily switch to Android.
One feature could be the difference between attracting those on the fence or not
That's totally me. I have an iphone 6. Not a 6+ or a 7. I don't need a to buy the latest apple thing. Before that i had a 4s so i've stayed with apple for two phones. But i'm not religious about Apple. I only have a macbook air just bought last summer. I like it but I have no interest in the macbook. After about 18 years of PC (before that all macs fyi). I don't buy media from itunes. I don't need apple music. I don't pay for icloud storage. I have a fire tv and a roku.
When i was deciding to get my iphone 6 i actually listed every app on my 4s to see if there was an android equivalent. The only missing app was Downcast the podcast app. And i'm sure there's a comparable podcast app on android not to mention, Downcast seems to have been abandoned by the author without an update in like 7 months and the app with lots of problems. But i digress. Point I'm the sort or person that uses an iphone but could easily leave as i'm not stuck in the apple ecosystem in any way. I've only ever bought 3 apps. One of which is Cesium (
Cesium Music Player) bought specifically because I hate what Apple did to the music app. That's quite telling. The only app i bought is because i had a problem with the direction Apple has gone.
I still use my headphone jack. You mention "one feature could be the difference." That could be it. I mean i use my phone as my only stereo in my car by way of an auxiliary input. No bluetooth. I'm not buying a new car in the next 5 years. So no headphone jack is a big annoyance. I also have other headphones that i still use like larger cans that are wired. I'd rather have both a jack and bluetooth.
Cost is an issue too with carriers not subsidizing phones. As someone that doesn't change phones often the subsidy matter since i never changed phones. if an iphone comes out at $800+ and some android phone does what i need at say $400 truth is it's almost a no brainer for me. That's why Google going all uber expensive with the Pixel now sucks. The nexus was a cheap option I'd have entirely gone for. Now it might be a wash.
The people that are on these forums are probably safe customers for Apple. It's the people in between that are going to be tough. I only ever leaned towards Apple because i used an iPod and why not carry one device over an ipod and phone. Truth is that's far less of a slam dunk now. No headphone jack. The ipod app i don't even use because it's quite cluttered and mostly pretty eye candy now. Now i'm pretty much open to be sold any platform. I'm still on iphone 6 though pretty happily though so though I'm able to be persuaded I still am a current apple user until i need a new phone. Hopefully not soon. Recently replaced the battery so hopefully it lasts.