The reason why GUIs became so popular so quickly after they were introduced is because text is not "just a better interface for a general use computer".
Like OP, I remember the days when command line was all you had, and even then we used stuff like TUI file managers to mitigate the pain of it.
But GUIs never took off as a UI for a general purpose computer, they became the UI for application on a general purpose computer. For them to be the former requires them to be programmable. Smalltalk is the best/most-famous example of a Graphical UI for a general purpose computer I can think of...
The main point is that for a general purpose computer the UI needs to integrate programming. Programming is how you use a computer. The shell (text) is currently the primary UI that inherently allows programming.
CLI is also specific to apps in practice, and I don't see any obvious difference between scripted CLI and scripted (with the likes of Active Scripting or AppleScript, or for that matter Tcl etc) GUI apps.
"The PinePhone is a smartphone that empowers users with control over the device. It is capable of running mainline Linux, features hardware privacy switches, and is designed for open-source enthusiasts."
Perhaps I simply failed to see your definition of "a general purpose computer".
Please say what rules must be passed to meet your definition.
Like OP, I remember the days when command line was all you had, and even then we used stuff like TUI file managers to mitigate the pain of it.