Hey, I said I may be wrong!
The way I hear people gripe about Apple's lack of compatibility, it seems like it must be impossible!
You are correct in some ways...incorrect in others.
If you want to replace hardware in a apple PC or Mac Laptop...you have to, or at least you had to at one time, buy from apple products to replace them.
If you wanted to replace a battery, had to get an apple product battery. so on and so on.
With android (or at least samsung)...There were many options of batteries I could buy to replace on if it went bad.
With PC...I could replace every part in my computer or make a whole new computer with different companies parts.
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However as he said...If you have been apple for years and have an extensive amount of songs you bought from Itunes.
You can have Itunes running on a regular PC and then get numerous programs to convert those songs to be exported/imported to an android phone....and vice versa
When I had an Iphone4 I had plenty of songs that I eventually converted/moved to my android.
There are times when I might get songs from Google Play that my wife wants...I can take them from my phone, to the computer, import them to itunes program on computer and then synch that to my wifes phone.