The more I come to terms with Powershell the more I learn to not think of it as a shell. Really Powershell is a scripting language for .NET that makes it easy to do sysadmin tasks. Powershell's weak point is interaction with programs outside the .NET interaction model (such as, ironically, "dotnet", the Core CLI). Powershell works great because the .NET ecosystem has evolved around a common object system.

Bash on the other hand is a way to invoke commands that allows scripting. Its weak point is interacting with data that's more structured than plain text. Bash works great because the unix ecosystem has evolved around plain text.