The keys I enumerated are sufficient to discover and execute all available operations in that style of TUI. You don’t have to type commands or command-specific keyboard shortcuts, like you have to in Emacs. It’s analogous to how in a traditional GUI you can discover and execute everything just using the mouse.
Like in the GUI analogy, you can then choose to remember and use the displayed keyboard shortcuts for frequently used operations, but you don’t have to.
It’s easy when you have a small amount of commands. And distributions like Doom Emacs is fairly discoverable too. But emacs have a lot of commands and while it offers menus, it’s only the surface level of what’s available.
Like in the GUI analogy, you can then choose to remember and use the displayed keyboard shortcuts for frequently used operations, but you don’t have to.