If you want to choose a programming language, there are hundreds to choose from. You could write a small program ("script") in Brainfuck. But that would be really annoying, and it would take you a long time to get anything done. Other languages may also take a long time to write, test, execute, and maintain. And they may be better at some things than others.

You have to step back and remember the point of all this. Why are you programming? To solve a problem, and make a human's life easier. What is the problem you are trying to solve? How can we make the human's life easier? In this case, it's "I want to combine bunch of programs together in a command-line interface, to make it easier to use these programs to get my work done on the command-line." So, what solution should we choose for this scenario?

Lots of different "scripting" languages exist (we used to call them "glue languages"). Today Python is the most popular, and before it was PHP and Perl. But who cares if they're popular? What are they good for? Why would you choose one over the other?

Python is a general purpose language which is easy to learn, easy to write, and easy to read. Well that sounds nice, but it's very "general" and not specific to our use case. PHP is a language designed for use in web development. Perl is a language designed for system administration-type tasks.

Bash scripting is designed for making it easy to combine already-existing programs in a command-line shell, with no modification or creation of programs required. The only "dependency" is the Bash interpreter (which happens to also be the command-line interface we started our problem with! how convenient!) and an existing collection of software tools that work with each other through a command-line interface. Every part of it is explicitly not designed to "make programming easier". Instead, it is designed to make "combining programs in the command-line" easier. The result is things like every single word you type is potentially just an outside program being executed, or arguments to that program. No other language has this quirky behavior, because they're not designed solely to make command-lines easier to use.

I know Perl well, and the language is fantastically useful as a system scripting language. It combines some of the best features of common shell scripting programs with more programming language-specific features. It is designed with shortcuts and "magic" to make quick work of command-line scripting tasks. But ultimately Perl was not built into the command-line, so its utility is always a bit stilted. Going between the shell and the Perl code and back to the shell isn't as flexible as if the Perl code was embedded in the command-line. Perl also doesn't have as simple a facility for pipes as a command-line shell does. Oh, and a Perl install is rather large, isn't available everywhere by default (anymore), and has all the usual dependency problems. So even though I know Perl very well, if I need to just combine existing programs in the command-line, I always use Shell scripting instead of Perl. (There are Perl shells which solve this problem, but then everyone needs to learn Perl, and Perl can be.... idiosyncratic)

You could also use Awk for a large number of general programming tasks, but again it's designed for a different specific problem: pattern-scanning and processing, not generally combining programs together.

So we use shell scripting to solve the problem because it was designed specifically for our problem, it's ubiquitous, and simple to use. You could use any other programming language, but it wouldn't fit our scenario as well. Once your use case changes, and you are no longer only trying to combine existing programs together, or the existing programs don't do what you want them to do, then you need to use a different language that better fits that new use case.