> The question is - why do we still need the terminal abstraction at all?

Because nobody is willing to put in the work to create a GUI toolkit that doesn't suck ass.

It's not that people want the "terminal abstraction". What people want is "Put <thing> on screen without me needing a PhD in graphics programming." That's why the dominant desktop interface paradigms have become TUIs and a Browser-In-A-Trenchcoat.