The text piping is just one small part and not the most important, instead its about sharing and processing any type of data with small tools that can be combined like lego blocks (and if there isn't the right lego block for a problem you can build your own). The UNIX shell is just one very primitive implementation of that idea (and yet it's still much more powerful than anything we have on iOS or Android).

In the "mobile app ecosystem", each application is more or less an island. It would be possible to achieve something similar on iOS/Android devices, but the entire "value proposition" of walled garden ecosystems isn't compatibel with this idea of open and creative computing. One prerequisite is that I actually own my device and can do anything I want with it, without the platform owner getting in the way.