story
Ethernet
(micro-)SD card
Keyboard
Mouse
Displays
Flashing microcontrollers (technically could be done over BT but it is a pain in the ass)
Gamepad
I've bought dongles/docking stations for all of these devices but it is a huge hassle when traveling, which is a use case a laptop should be able to excel at. Adding just a single USB-A port and HDMI would be a complete gamechanger for me. Apple wouldn't be able to sell as many of their $70 dongles though.