Why must science be open to change?

Nearly everything in science is considered a "theory" because there isn't enough evidence to prove it to be a fact. So, if more evidence is discovered, a theory will become a fact, or if evidence is discovered disproving a theory, the theory is no longer even valid as a theory.

everything in science is all based off of a theory because there isn't enough evidence to prove it to be a fact. So, if more evidence is discovered to prove it, a theory will become a factual, or if evidence is discovered against it, aka disproving it a theory, the theory is no longer even valid as a theory because theres factual evidence against it. so, knowing this scientists have to be open to new ideas in order to find out the "truth" or to build upon.