A command-line tool is nothing more than a script that maybe parses some input from the program's arguments or from stdin and then does something useful. Naturally you want to have the libraries you're used to available and the best language for CLI tools is the one you already know.

Building CLI tools in C/C++ is silly. If you like Rust/Go, sure, knock yourself out.

But the obvious choices are the scripting languages with runtimes that are already distributed as part of the OS .On Linux most CLI tools are built in Python or Perl and Ruby or Node.js are decent choices too.

JVM languages aren't an ideal choice due to the startup time, but given the size of the ecosystem you can find a library for pretty much anything you need and now we've got GraalVM to help with the startup time. So not a bad choice either.