No one needs an iPhone. No one.
It wasn't that long ago that no one carried a phone around- they were either on the wall or on a table, and you went to a building to make a phone call. He doesn't need to pay several hundred dollars for you to have access to videos and the internet everywhere you go.
I imagine your flip phone doesn't take videos or pictures, either, and if it does, they aren't good ones. Dad is smart - you shouldn't have a way to take them and send them to your friends- this is how kids get in huge trouble.
But mainly, your Dad is giving you something, and when you are in a position to pay your own rent, your own health insurance, your own clothing and your own food, you can choose whatever phone you want. For now, appreciate what we all thought was way into the future - if you watch some Star Trek episodes, they had communicators that were like flip phones,and we never thought we'd ever have one of our own. And now you do.