That's your problem. You shouldn't switch to Android in the first place, android tracks you, sends your information to remote servers, is totally unreliable too. Believe me, I've studied it. If you would've stayed on iPhone, this wouldn't happen. So, don't be blaming Apple. Blame yourself.
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All of those seem okay to me... They all work perfectly. Instead of finding flaws constantly, try looking at what they do. You go code an Assistant that is amazing, a maps app, or a message service... I'd like to see how it comes out for you.
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You're completely wrong. It'll be cached to apple servers as an iMessage until a set amount of time.
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Then don't move from iPhone. I don't see why you would in the first place. Android harvests your data... So stop complaining. If you hadn't switched, this wouldn't have happened.