I think that there are definitely valuable/valid use cases for the software in the OP, but I think that the built in bash tools can get most people most of the way there. And learning the common bash/shell conventions is way more valuable than learning a custom tool that some distros/environments won’t support.

If someone already uses aliases, creates some custom scripts, and sets some useful environment variables (along with effective use of piping and redirection) and still needs something more specialized, then getting a new tool could help.

The downsides are a reliance on another piece of software to use the terminal. So I would only use something like this if I had a really solid and specific use case I couldn’t accomplish with what I already use.