Theory doesn’t mean what people think it means.

Culturally, we misunderstand theory to be equivalent to “hypothesis,” meaning “We have an idea, now we need to prove or disprove it.”

But accurately, theory means “We have a framework of interrelated ideas that fit the observable evidence.” In that sense, evolution is an EXTREMELY well supported theory.

Gravity is also a theory. So are general and special relativity. So is all of quantum physics.