Real, proper parallelization in PowerShell Core (and Windows PowerShell, for that matter) can be achieved in many different ways. You could, for example, use the threading namespace of .NET and try multi-threading yourself. Or you could use the more PowerShell-y way of using runspaces and their built-in throttling capabilities.
This recipe shows you how to convert long-running scripts into parallel executed runspace jobs so that you can benefit from powerful multi-threaded processors.