I’m glad my phone is so old. Nobody wants to hack it. I don’t think it even has a SIM card in it.
All cell phones have a SIM card.
Encrypted in it is the code that identifies the device to the network.
That’s why only your phone rings when someone dials your number even though the signal is coming over the air on radio waves and theoretically can be “answered” by anyone.
Cell phones old enough that this couldn’t theoretically affect them do not work with the current networks.
As for nobody wanting to hack it... People will hack connected pet food dishes and refrigerators. Your cell phone is considerably higher on their list of desired targets.