Safe to delete Apps.ppkg?

The following’s pasted from https://superuser.com/questions/1659902/safe-to-delete-apps-ppkg (moderator edited URL)
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I must reduce HD disk space. How safe is deleting Apps.ppkg? Its size is 3.6 GB. I use Windows 10. I must double check because another program file usmt.ppkg MUST NOT be deleted.

I read [this abstruse explanation of Apps.ppkg, but I don’t understand it.

It doesn’t clearly advise if deleting is safe. In actuality, the last sentence suggests that deletion ISN’T safe — because if deleting is safe, why would you need make “a backup of the file on external storage”???