A shell is a REPL. If your language makes actually writing things in that REPL hard, it is definitionally bad at Shell Stuff. I find it significantly easier to write code in C# and then transliterate it to PowerShell than to actually write PowerShell. That's a disastrously bad situation for a shell.
Yes, I am calling you out. I am challenging you to provide concrete examples where Powershell has less discoverability than bash or zsh. I am challenging you to explain why ISE - an environment designed specifically to combine REPL with script authoring - is "unacceptable".
And please, no more hyperbole or condescending remarks.
I learned Powershell mostly from Get-Help. I can usually figure out where to look for a command based on the naming conventions - essentially (one of x verbs)-(one of x nouns). They aren't always fantastic, but for example, Select-String is a little more obvious than grep.
But personally I find working out command names in powershell much more sane, because of the Verb-Noun pair naming convention.