First of all, the two examples you present do not do the same thing. The Powershell version preserves paths and excludes more patterns than your find | xargs example. The right way to do this is to just use robocopy.

This example has targeted a very specific deficiency in the way Copy-Item works. I could similarly point out that the following Powershell command would be much more difficult in standard unix tooling:

  Get-WMIObject -Computer $remote -Class Win32_Product | Where-Object { $_.name -like "7-Zip*" } | select Version

Which gets the version(s) of 7-Zip installed on a remote machine.