Shortcuts - non-descriptive and strange error message with Open App action

I’m getting the following error message when I try to use the Open App action in Shortcuts

This action can only be run from inside the main shortcuts app because it launches other apps.

Googling the error message yielded a Reddit thread that suggests that I can’t use this action because I use Screen Time to disable Safari on my iPhone (Digital Minimalism, etc).

Two (admittedly ranting) questions that may not have straightforward answers:

  1. How on earth is the error message related to the cause of the error, or attempt to communicate it in any way?
  2. Why does disabling Safari affect opening other apps using Shortcuts? Is it related to the Workflow days, where everything was essentially a URL scheme in disguise?