If God is not capable of creating in six days then the other miracles of the Bible get called into question as being real or just fables.
In my experience, the Biblical inerrancy argument for Genesis soon falls into a hopeless swamp by trying to dispute science with various rhetorical evasions and references to oddball websites that claim the science is wrong.
It seems to me that, taken in full, modern science demolishes Genesis on the details but endorses its essential point. This seems to me an extraordinary result. Call Genesis a fable if you wish, but it is a fable that conveys the truth of Creation.