/Apps is a hodgepodge that saw its shadow yesterday morning, thus foretelling a
looong winter in Apple-land.
- The Apps folder looks like /Applications
- Apple apps look like /System/Applications/Preview.app
- 3rd party apps look like /Applications/Microsoft Excel.app
- The Utilities folder looks like /Applications/Utilities
- Apple utilities look like /System/Applications/Utilities/Activity Monitor.app
- 3rd party utilities look like /Applications/Utilities/NoSleepHelper.app
Got it?
I"m surprised by your Luminar 3 d/l; its dev apparently didn't fully digest what Apple hath wrought. I wonder if your ability to trash it would have been compromised had you left its path intact?
I would be even more curious to see if the installer could write to /System/Applications. Supposedly that is on a READ-ONLY volume. Much of my confusion is a result of APFS volumes and volume groups, how they are identified/addressed, and items such as the "in the box" app icons found in /Applications that disguise virtual locations.
Unless I missed it in the lengthy posts above, it was my understanding that the two Applications folders are the option to have an application available to all users—/System/Applications—or just available to a specific user—/Applications.
This arrangement would avoid the need to install an application multiple times, once for each user.