Ubuntu is a product of Canonical which are a pretty evil corporation and a submarine of Microsoft. What they don’t leech off Debian is proprietay and lock-in.
For those who don’t understand: cage is a kiosk wayland window manager, which means it only runs one program in the foreground and in fullscreen.
foot is a graphical terminal emulator.
So the joke here is to run a terminal emulator in fullscreen and kiosk mode on a wayland wm from tty, which, at first sight, looks exactly the same as just tty. So you use wayland for a lookalike tty session, which is a nod at OP’s image which states you wouldn’t run a tty on x or wayland.
(But cage+foot has mouse support, nice fonts, can launch graphical programs, etc., and has itself established as a kind of rescue shell for tty-less kernel distributions)