alt Hacker Newsthe first and second are graphics terminals which is muddling up the definition. of course they were called terminals back then until we decided to make a distinction. what they are called is not the point. the point is the distinction. for today's discussion terminal means text without graphics, as shown in the third video.
the real question is why are we still using text terminals?
the short answer is that on remote connections graphics is still a performance issue. in fact the popular solution to making remote graphics performant is webbrowsers. they are the graphical terminals of today.
if i want to build a graphical interface to a remote service, then i build a webinterface.
locally, the answer is historical tools, and that text interfaces are easier to develop and still more efficient to use. but not easier. especially commandline tools without an actual visual interface.
i just had this situation. the dolphin filemanager has a feature to add tags and comments to files. the interface is very clunky. but there is a commandline that lets me set those tags and comments which is much more efficient once you learned how to use that command.
As for the third example, note that the programs discussed here (arguably TUI) are unlikely to work on this type of terminal. Unless the program has a built-in mode that allows it to run in true command-line mode (arguably CLI). Just like vi/ex.
Of course, these were just examples to show that a computer terminal didn’t have to - and doesn’t have to - be like a VT100 or similar. And I realize that nowadays, when we hear the word "terminal," we tend to think of something like a VT100. Especially since the Linux (kernel) includes emulation for something like that.
However, historically, the first devices to be called computer terminals (and to enable interactive operation) were typewriters and teletypes. That is why one of the names given to newer CRT terminals was "glass teletypes." To distinguish these terminals from their predecessors, they were also referred as video terminals (VT) or video display units (VDU) etc.
Note that in addition to built-in VT102/VT220 emulation, xterm also includes built-in Tektronix 4014 emulation, which, to use your terminology, is a graphics terminal.
But on the topic, IMHO those "text terminals" represent the lowest common denominator, and using them as a user interface causes the least friction compared to true GUIs. For example, after booting Linux, I can basically start using those TUI programs right away without having to install or configure a graphical environment (X11 or Wayland). Remote computing also causes less friction and can essentially be used out of the box.
And TUI programs, like GUI programs, also make it easier and faster to explore compared to programs that run exclusively in CLI mode.
Personally I regret that Plan9-style computing and Oberon/ACME user interfaces didn’t become mainstream...