There are so many things I could say, but let's just start with the user experience on Catalina. If you try to open an unsigned app, you get a Gatekeeper alert

There are so many things I could say, but let's just start with the user experience on Catalina. If you try to open an unsigned app, you get a Gatekeeper alert that says "macOS cannot verify that this app is free from malware" and tells you to move the app to the Trash. (Of course we see from the linked article that the phrase "free from malware" has always been misleading.) Whereas for a notarized app, the Gatekeeper alert says "Apple checked it for malicious software and none was detected" and allows you to open the app. So to claim that this is not any kind of "approval" is just patently absurd.