iMessage sends and receives text messages. That's a pretty weak lock in - there pretty much isn't a mobile phone made that it can't interoperate with going back a decade or so.
Maps, I'm curious as to how this is a lock in, or who it is who is desperate to get Apple maps on their non-iOS device but I'm sure as this is an Apple issue you'll be able to point me at where I can get the great official Android Maps / Navigation app for my Kindle Fire then? Oh yeah, it's official licensees only.
And the version of BlackBerry messenger for iOS? Or Android?
And I can access Microsoft Windows Phone Rooms from Android can I?
Specific functionality offering competitive advantage are only ever shared by people when it's in their interest. That's not an Apple specific issue, you'll see the same with pretty much every device.
And physical hardware connectors - Micro-USB as a standard for charging is fine but the fact that they both have a Micro USB port doesn't mean that you can use Android peripherals other than a charger with a BlackBerry or Nokia Lumia.
And for chargers - kids don't need dozens of chargers, in most cases the one in the box will be fine. If not $10 on eBay will get you another one - hardly a massive issue when we're talking about phones generally costing hundreds of dollars.
The reality is that device change has always had barriers but Apple's don't seem to me to be significantly worse that anyone elses.