Devices 75 years ago weren't designed to be millimeters thick. If you have a removable battery, you need the walls of the battery to be thicker to prevent punc

Devices 75 years ago weren't designed to be millimeters thick. If you have a removable battery, you need the walls of the battery to be thicker to prevent puncturing it. You have to have extra thickness for the battery cover and for the wall that goes against the battery. You need a contact interface for the battery instead of a flat flex cable. There's no way to make an iPhone as thin as it is with a removable battery. You can argue that no one needs a phone that thin, but regardless, I don't think it has anything to do with planned obsolescence.