I recently had to uninstall some apps and it’s common for apps to litter files throughout /Library and ~/Library. The UX from early MacOS days is you can drag/drop the App to the Trash Can to uninstall it. Does MacOS actually clean up the misc. files applications leave at some point?
Wait wat So macOS is as shitty as Windows in terms of app install? Anyway, accepted wisdom now is that applications should only run containerized, which would make uninstall as simple as deleting the container.
The stuff in ~/Library is caches + preferences + any other data. Deleting an app on macOS, even back in the day, did not delete the preferences.
The problems with Windows is that you needed an installer in the first place, and then an uninstaller, and then you couldn’t move an application to a different location. On a Mac, you can still just drag the application to the /Applications folder, or somewhere else, and then delete it later. The user data remains.