There is no such thing.
The point of there being a notion of the Great American Novel is to elevate fiction. It’s a target for writers to aim at. It’s a mythological beast, an impossible mountaintop, a magical vale in the forest, a place to get storytellers dreaming of one day reaching. It keeps you warm when times are cold, and times in the world of writing for a living are mostly cold.
Both essays seem to start from the idea that everyone takes these conversations seriously, and therein lies the problem. In fact, the writers are the ones taking it seriously. The rest of us just want to have fun.