One of the greatest scientific minds of all time, Isaac Newton, is quoted as saying (circa 1720):
In nearly 300 years since Newton, scientists have found many smoother pebbles and prettier shells, while at the same time "the great ocean of truth" has seemed to expand to now include the entire Universe, and possibly beyond...
So, compared to that ever-growing "great ocean of truth" we know even less today than Newton imagined he knew in 1720.
To answer your specific question, a scientific theory does not require perfect knowledge to either confirm or falsify.
It does require that its predictions are confirmed by observed data (aka facts), and this standard is met by the evolution hypothesis.
So it's a scientific theory.
“this standard is met by the evolution hypothesis”
But no evolutionary theorist has ever met this standard.
They have never identified the phenotypes and genotypes of the process of speciation.
And to claim that nature can “select,” as though nature were an agent rather than a mechanism, is nothing but a slight of hand.
You’re like the audience member who believes the stage magician doing his trick and then proclaiming “I speak the truth: he rabbit came out of the hat because he appeared, from nowhere, in the hat.”