>"I recently had to uninstall some apps and it’s common for apps to litter files throughout /Library and ~/Library."
For ~/Library your application may often put its preferences in ~/Library/Preferences/ and partly in ~/Library/Application\ Support/. That's entirely normal and expected. But, no, for /Library that's absolutely not common. Very few applications run as an actual "installer" and even fewer of those request admin privileges. But it is annoying those few times some software actually does it. At the least you can always tidy it up yourself on the command line.
For ~/Library your application may often put its preferences in ~/Library/Preferences/ and partly in ~/Library/Application\ Support/. That's entirely normal and expected. But, no, for /Library that's absolutely not common. Very few applications run as an actual "installer" and even fewer of those request admin privileges. But it is annoying those few times some software actually does it. At the least you can always tidy it up yourself on the command line.