Except Classic Mac OS never had this. You'd sometimes need to do arcane rituals like "re-bless the system folder", but they were entirely GUI-based arcane rituals that involved double-clicking icons, opening and closing windows, and dragging files in and out of folders.
Text interfaces: streams of discrete objects (characters) with some having special purposes
GUI: A matrix of pixels + a set of of rectangles with special properties attached.
If you want to quickly write a program, text is the way to go. Most developers are scratching their own itch and already know the system. They may surface a few GUI settings (if it's GUI), but no one wants to build a complete GUI ecosystem on top of Linux (unless you go fo a restricted version like ChromeOS or Android).
And with scripts, you can quickly write your own software by using existing ones. It can be your very special computing world.
There was no other, simpler interface. And the whole system was much simpler (and less capable). The graphical hardware was way simpler and fully in-house, unlike the current GPUs that are third-party and evolve quickly.
Exactly, there was no other, complicated interface. Except in 1991-1995 when System 6 was going to merge with AIX and be A/UX and Apple was going to merge with IBM and it was all briefly very weird.
Except Classic Mac OS never had this. You'd sometimes need to do arcane rituals like "re-bless the system folder", but they were entirely GUI-based arcane rituals that involved double-clicking icons, opening and closing windows, and dragging files in and out of folders.