They only has to develop one app for iOS, whereas they have to essentially develop hundreds for android. It's pretty self explanatory isn't it?
Erm, no. Every now and then you need to do a 'IF using this version or great -> do this -> if not -> do this', but to be honest that's mainly only really for permissions as they changed around API23 to the iOS way of asking when needed. Aside that, it's pretty much one set of code and off you go.
Look at the adoption rate of iOS versions, iOS 11 is already on over 25% of devices in the space of a week, only like 15% of Android phones are on Nougat which is over a year old.
I know it's a small sample size, but I have two apps around 1,000 installs mainly used in the US (and UK) and they both have Nougat around 37%. Clearly not as good as iOS, but a healthier figure than the perhaps the global figures.
It must be a nightmare on Android, having to constantly target older API’s and OS versions.
See above, no not really.
Android's biggest attraction is also it's weakness. I have found out now that with all these choices of all these phones, it means no coherency, lots of fragmentation in users. It's a problem for the platform that they will never fix, and frankly, no way to.
Can you give an example? As a lone user, how the fragmentation is an issue? I've never noticed a problem as a user myself? (I don't see slower updates as an issue, which is the only thing I can think of. We all get security updates quicker and more reliably now for example.)
I would really like to learn to code for iOS, yes because they do spend more apparently and also because if I make an app for Android, I would like to be able to make an iOS version, but also to see how different it is. I have seen some devs say Android is easier, I see some saying iOS is easier. I think often it's just a choice by a firm 'oh, we've mainly got iPhones, lets just do an iOS version and we'll do Android later'.
As for passwords, just get LastPass. Uses fingerprint sensor to log me in to all my apps.
As for features, my iPhone using friends where very annoyed, seeing my TomTom Speed Cams overlay in action, that iOS couldn't do that...