So I am not a developer, however I thought it would be worth asking why there is no support for background recording on IOS even though other providers, such as Android, allow this feature. The main purpose for which this feature would be useful would be for dash cam apps which record video when driving. I currently am using Driver: Dash Cam & Cloud Sync however this app is restricted on IOS in that it is unable to record when you are using other apps. This is frustrating if when driving you chose to try and use navigation, or music, because apple does not allow background recording. According to the FAQ for this app, this is not a problem on Android simply because background recording is not restricted.
Background video recording
Well, I'm not Apple, but I think it is unlikely that you'll ever hear a reason for their design decisions. What you'll usually hear is that if you want a feature, use the Feedback Assistant to request that feature - outline your use case, what you can do, what you can't do, why you would like to be able to do it.
Often, decisions like these are made to improve the overall user experience of the phone; it is quite easy to drain the battery rapidly if you leave. video recording on inadvertently.
You may contend that the user should be made the final arbiter in this decision (it's my phone, and I'll drain the battery if I want to!), and that is so on other platforms, but this is Apple's design and Apple make the rules.