I am partial to your sentiment but I don't think writing all the terminal handling code in elisp gives us code that might be too interesting to read (to me at least).

Understanding the VT state machine and all its quirks and inconsistencies is not high up in my list of code I'd like to learn. It is good it is packaged up in a library and emacs is just a consumer of it.

libghostty will have excellent compatibility and features rather than an elisp implementation that maybe half baked.

I stopped living in the world of turtles all the way down. Now I'm more like, hey is this is good library ? Is it integrated well ? It does not matter if it is in zig, rust, c++, lisp, scheme, ...

Jitted Elisp for itself has much more power because of function composability than badly reusing libraries without even a common API like OLE/COM under Windows. You are just creating silos badly interopearting together.

Even 9front has something like 9p, namespaces and everything it's truly a file. Even GNU/Emacs under Hurd doesn't have its full power developed until the GNU people ditch Gnuplot for their own GNU-born capable 3D plotutils and the like.

And today given the speed of jitted Emacs if I were the Calc maintainer I'd try to write a PNG/farfbled (or whatever it's called) plotting tool in pure Elisp, with both TTY and graphical outputs.

Depending on non-GNU, external tools it's holding GNU and Elisp back.