Ah, but it isn’t. All the empirical data from just about any science show it to be false. To suppose otherwise is epistemological nihilism: facts are just opinions, and anyone’s opinion is as good as anyone else’s.
I find the flat-earth test to be valuable. If you substitute “the earth is flat” for whatever fringe claim you wish to favor, does it make the “debate” silly? Why? Can it be that the data do indeed matter?
In the current case, should we seriously entertain flat-earthism as a live hypothesis to be debated?