This error exists because Apple has effectively made app notarization mandatory, otherwise, users see this warning. In theory, notarization is straightforward: upload your DMG via their API, and within minutes you get a notarized/stamped app back.
…until you hit the infamous "Team is not yet configured for notarization" error.
Once that happens, you can be completely blocked from notarizing your app for months. Apple has confirmed via email that this is a bug on their end. It affects many developers, has been known for years, and Apple still hasn't fixed it. It completely elimiates any chances of you being able to notarize your app, thus, getting rid of this error/warning.
Have a loot at how many people are suffering from this for years with no resolution yet: https://developer.apple.com/forums/thread/118465
Other than developing my own (without using any other OS...) which is a ... significant ... task, there's not much other option. YMMV.
As a Linux lifer I agree that the hard diamond surface of the Mac desktop has a solid feeling to it. The Linux way is harder and also more brittle. Windows and Linux are both better than MacOS even as a desktop as long as you do not look at the in the wrong way. The thing is I have only minor problems doing that on either Linux or Windows, but the walled garden of the Mac, Android and iOS is a joke.
MacOS is designed to be a somewhat stable desktop, that is good. It is not a better Unix, it is a political stance that means hacking will forever die.
Linux developers seem to almost-universally believe that if the user doesn’t like it or it doesn’t make sense then the user will fix it themselves either via configuration files or patching the source code. That model works fine for users with a lot of knowledge and time on their hands. In other words, it’s an operating system for hobbyists.
MacOS, for all its faults, is still pretty easy to use (though not even close to the ease of use of Classic Mac OS 9 and earlier).