I see now that not all the PS files are for tests, there's one adapter PS module for compatibility. But that's still damning: If Microsoft themselves are build

I see now that not all the PS files are for tests, there's one adapter PS module for compatibility. But that's still damning: If Microsoft themselves are building their PS modules as ConvertTo/From-Json wrappers for native CLIs (or being shipped at all, like winget's PS module), instead of shipping C# cmdlets and a domain model for .NET, then PowerShell is superfluous and we should be dropping it, even on Windows, for a JSON-aware shell or a more common shell with tools like jq.