If that load of rubbish that moved my files around becomes mandatory, I won’t be able to help the community any more.
The Arduino might be quirky and it might be dumbed down to the point of being a thorough nuisance, but if a new installation wiped your files, you didn’t have them in the right place to begin with.
From the ‘Learn’ article about installing the libraries:
Important: This is NOT the same ‘libraries’ folder that is part of the Arduino IDE. If you put the OEM libraries in there, they will work but when you update the Arduino IDE, by default it installs in a completely new folder and you will have to move or copy these libraries. For that reason it is not recommended.