One of the cornerstones of the unix filosophy is extensibility, and is great piping all of these programs one onto the other, like a assembly line folding aluminum onto cans. But the world isn't the command line, nor some lisp machine, because programmers define the specifications and estrucure of data as the want.
How should all this different programs even live along? Because not even all programs even consider this method. Vast mayority of GUI Apps are designed to be its own data ecosystem, cause i would be neat if i could reuse their subroutines for my purposes (like plugging GIMP's filters onto Kdenlive pipeline, or inspecting CAD software path finding wiring algorithms)
Here i am talking of modular design, maybe even replaceable parts; but i am skiping a lot of implmentation.
Although ou got monolytic black-boxes programs like ffmpeg, yt-dlp, imagemagik. They work so well, and their interface is very accesible, even if their internals are whole opaque.
You go too programs like Unreal Engine, Blender, Davinci Resolve, LaTex; they are walled gardens, but ther internal ecosystem is rich in scripting, and as factories, they spit a finalized can render product.
Dont even talk about interface. Is the low caliber pipe of plain text enought? By the way, Wich one? ini, cvs, xml, json?; Should we consider creating specifications, binary formats? Isn't that really propertary? But midi just works so well; Are you ready to enter the world of local net protocols?; Let's imagine more: Not delivering data, but access to data, and sending the subroutine-as-a-primitive that parses a shared memory location of opaque data structures.
Sometimes i feel unghinged. The world is spinning all without me, and people are working really well on those conditions; i am. The "People will use whatever we produce" has a positive side too, so look at the plethora of scripts that do extend walled gardens. Look at the other side of the fence, at linux ricers and their adventures at config land, where they see the vast lands between mouments of programs, Did you know that deep into the etc folder, Xorg created a programming language for their config files? Its so funny
I got stuck sorry. If you promise me staying another paragraph. Some lispers at Palo Alto did this, and created this graphical enviroments where all the data was passed as pure messages, though a byte code custom cpu, and all its partes could be changed, inspected, debugged and customized; GUI its not for the weak, its for productivity on the less keystrokes