This, like history, is one of those dogmatic aspects of state education where only one side get taught and implicitly assumed to be the only one. Geography books need one big asterisk in so many sections
If Americas are one continent, then Afro-Eurasia must be continent. And end up with the four continent model with continuous landmasses.
If isthmuses make continent, then get the six continent model with tectonic plates.
If can split into non-geographical regions, then Europe and Asia can be separate continents and get the seven continents in the US model.
This, like history, is one of those dogmatic aspects of state education where only one side get taught and implicitly assumed to be the only one. Geography books need one big asterisk in so many sections