Use Python for Scripting
hypirion.com
hypirion.com
Personally though at the point where you need a true cross platform scripting language in the shell I'd just install something like powershell or nushell.
... When does this happen, anyway? When I am in a "scripting" mindset, it's because I want to enhance my machine, not publish software. If I am thinking about "cross platform" then I am also thinking in terms of "programming" and "development".
(And, you know, awareness of "the shell" is probably a lot lower among Windows users than Linux and Mac.)
I think you're correct about windows users in general but if a user is likely to script in python I'm fairly certain they'll be aware of the shell. And the shell in windows is massively powerful with powershell.
Either way both powershell and nushell are cross platform meaning their scripting are too, unless you're doing something OS specific.