Write Posix Shell
when the problem you’re solving is small, well defined, and unlikely to change, consider shell.
when the problem you’re solving involves linux, text processing, or managing files, consider shell.
This is what Luke Smith taught me: a shell script is often enough. Of course, you can use Ruby, Python - heck, even JavaScript. But often, you don’t need it, as a simple shell is more than enough.
What FreeBSD experience added to that is portability. I try not to use bashisms anymore (thanks to shellcheck), as POSIX is good enough. If it’s not, maybe shell is not the best approach for this problem. Portability and lack of dependencies will pay out eventually.