I mean, neither will `ls | rm`, and a myriad of such combinations if you try them blindly, but it's unreasonable to assume that every combination of commands wi

I mean, neither will `ls | rm`, and a myriad of such combinations if you try them blindly, but it's unreasonable to assume that every combination of commands will work in the simplistic way you expect them to. Tools like xargs exist to fill that void, and it allows the tools themselves to work independently. Developing a set of tools from scratch that share a strict design principle is much easier than enabling an ecosystem of purpose-built tools developed over decades by external contributors to interoperate with each other. Leaving the exchange format open is a reason this still works so well today. Or would you rather use XML or whatever format was popular 40 years ago, have to adopt a new format whenever the previous one becomes outdated, and deal with compatibility hell when tools support different versions of the format?