If your oil painter worked a year to "create" the painting and then claims he created it himself, does this also mean, he made the colors himself and that he has woven the canvas himself? That none of his pupils helped color in the boring background?
The canvas is a bit overdone, but painters in the olden times did often mix their paints themselves. Some probably even made their own brushes.
In game creation there are engines used most of the time. How can a game developer even claim to have made a game, when 99% of the code is in the engine? And yes, there are devs that try to hand craft their own game engine. While there is no such reverse tag, you can imagine one: no-engine. There are engine meta tags.
People against slave labour gen ai might be surprised what can be considered such. I would not surprised if all or most game engines have some code in it that was created with the help of ai. And with the vegan mindset to avoid all things with even traces of animal ai, now that would be interesting.
I agree with the percentage being not applicable. See my example with the engine code. But I also think that use of ai code should not be put together with use of ai content, when classifying "ai". Creation of code is so much different from creating art. In other words: if you successfully can write a prompt for an ai to make the code do what you want, than this form of ai gen is not really different from translation natural language into machine language.