I always wonder what another interaction scheme would look like if it weren’t for “click”, I’ve always wondered about tunnels or roads, like we do in real life, to continuously travel toward a destination, rather than discretely click.

There is the filter graph or node graph, found in things like Unreal Blueprints, Blender or ComfyUI. That's kind of the GUI version of a pipe and even quite a bit more powerful as you can have multiple inputs and outputs. But it's just something individual apps implement, it's not something any OS has as a native primitive.

For something a little more CLI-like, there is Archy, which is kind of like Emacs, where programs are just commands that operate on the same bit of data, not complete separate things, but that never made it past some prototypes and it's hard to see how it could work for the whole OS, where you have to deal with a wide variety of file and data formats. It had a commercial predecessor with Canon Cat in 1987, but that also ended up a dead end.

Another thing is Project Xandau, this is more of an alternative to the WWW than just a GUI/OS, but it would have had some neat properties like links to and quotes from other documents being actual references to those documents, not copy&paste. But again, nothing but prototypes.

Unix shells just assume everything is text, which makes all the small tools possible. But the GUI world contains a lot more than just plain text, which makes it difficult to come up with any universal scheme that can have the same flexibility. Even HTML, which is the closed thing to an universal data format in the modern GUI world, fails quite miserably here as, as it ends up being just a format for content consumption, not a format that is used in the creation and management of the data.

At the current pace we'll have AGI long before we have any real innovation in GUIs. Will probably end up with StarTrek like interface sooner or later where you just say what you want and the AI figures out how to get it, ChatGPT already isn't that far off and can handle a lot of simple grep/sed like tasks quite well, even shell one liner can be produces with a reasonable rate of success. What's is a way to let it access and operate on local data.