I have the key fob. As I have auto-present door handles, it's essential for that. I just walk beside the car and the door handles swing out. Without the key fob that would not happen. The fob also makes opening the electric frunk and trunk a breeze. One click on the key fob does it. The key card does not do that and one has to go through several steps with the phone app to open the trunk or frunk.
I know my case is not a good example for others who don't have the auto present handles or electric frunk and trunk, but if anyone is thinking of making these mods, the key fob is a great help.