So when is it okay to move from one item on this list to another? Obviously, if a task can’t be accomplished with a more-preferred way, you move on to a less-preferred way.
If a less-preferred approach offers far superior performance, and performance is a potential issue, then go for the better-performing approach. For example, Robocopy is superior in nearly every way to Copy-Item, and there are probably numerous circumstances where Robocopy would do a much better job.
Document the reason for using tools other than PowerShell in your comments.