Only iPhones can use iMessage. iMessage uses a data connection rather than SMS or calling. OP lives in a different country and international SMS or calling would cost a lot of money, but a data connection does not. The only way of communicating with certain people without incurring extra charges is for OP to use iMessage over a data connection.
What does a contact list have to do with a phone? Does the iPhone lock you out of even proper contact management?
No, contacts as in the people they want to contact.
What does that have to do with the phone they own? I still don’t get it.
Only iPhones can use iMessage. iMessage uses a data connection rather than SMS or calling. OP lives in a different country and international SMS or calling would cost a lot of money, but a data connection does not. The only way of communicating with certain people without incurring extra charges is for OP to use iMessage over a data connection.