the limitations of an "emulated typewriter" keeps things from becoming too complicated. And also allows you to control it using just "echo". It has its warts, but I still think it's a good system.
We have GPU accelerated bit-mapped displays with 3D rendering, general compute capability and gigabytes of RAM. Create a GPU accelerated canvas in a buffer, load assets like text and bitmapsinto memory and issue rendering commands like a graphics engine. This way you can render text at a 35 degree angle on top of other text on a bitmap on a freakin rotating cube. Draw whatever you want instead of trying to GPU turbocharge a typewriter cosplaying as a dot matrix printer. To me that's backwards thinking.
You can still build an all text TUI but with better text control and graphics. This can work over a 2-way pipe like TCP, websocket or whatever using RPC's.