Gamecube doesn’t have enough RAM to preload everything at startup like that, you have to go through the menus and pick a game mode and map to load.
Surely if it needed that startup load anyway, then Sakurai wouldn’t be saying he turned the license down in order to get players in the game faster. I’m going to trust Sakurai’s word here!
I really miss the keyboard on my old Motorola Droid 2. Still wasn’t any good for gaming honestly, but it’s way better for typing than a touchscreen.