I understand this is chaos, but it's chaos because it has to be. There's no way to move users from an world of opaque "if it's an application, it can do anything it wants" to a world of "applications should ask me when they want to do something" transparency. The idea that Apple doesn't care about the Mac because it's trying to explicitly improve our privacy and security is … weird.
I expect applications to have access to my desktop. I do not need to be asked. It would be like asking permission to access my clipboard, or use my speakers, or read my keyboard. If you bombard users with dialogues for every little thing, all you will do is train them to habitually click yes . Now you have lowered security, because users will ignore the more serious warnings too. And you've wasted everyone's time in…
You should only ever expect the user to have access to the desktop and, even then, the only apps that would ever prompt for access to the desktop are those that aren't updated for High Sierra and above. On the latest versions of macOS, the Desktop folder is shared by iCloud. This is definitely not an instance where security has been lowered nor is this the standard behavior of the new OS.