“OK, so the Earth is round.”
Frisbees are round, the Earth is an oblate spheroid.
"So what?”
So you’d think the guy who built it would at least know the shape, right?
“Does that void the rest of the book...”
Well, yes. The ‘infallible’ word of god is found to have failed.
“BTW, those references about the flat earth could have been added [to the Bible] during the Middle Ages by superstitious Europeans.”
Why, YES! And what does that mean?
IT means God did not preserve his infallible word.
It means at least some of the content comes from people we can’t identify, and their knowledge is limited to whatever humanity knew and accepted at the time of the edit.
It means you have NO WAY to know what part’s god’s word and what part’s Paul’s and what part’s the work of a drunken monk scribe who was left without supervision for a month or two.