You assert a dichotomy where no split really exists. Qt the end of the day, things like tr or xz or sed invocations are not part of bash as a language. They are seperate tool invocations. Python or any other programming language could have things hidden in them just as easily.

And the other major issue here, is that xz is a basic system unit, often part of a bare bones, ultra basic, no fluff, embedded linux deployment where other higher level languages likely wouldn't be. It makes sense for the tools constituting the build infra to be low dependency.

And yes. In a low dependency state, you have to be familiar with your working units, because by definition, you have fewer of them.

Unironically, if more people weren't cripplingly dependent on luxuries like modern package managers have gotten them accustomed to, this all would have stuck out like a sore thumb, which it still did once people actually looked at the damn thing*.