Darwin's theory of Evolution has never been proven and Lucy was an embarrassing hoax.
The
Theory of Evolution describes the observed fact of evolution (descent with modification), resulting in the best explanation for both the present levels of biological diversity and the observed ~3.6 billion year history of life.
A Theory is a thoroughly tested explanation of a phenomenon, providing a framework explaining the observed facts and making useful predictions. There's the Germ Theory of Disease, Cell Theory, Atomic Theory etc, etc.
Theories are never proven. Facts are proven (in a colloquial sense). Theories provide the explanation of facts. The Theory of Evolution has been proven to describe the facts of evolution in the same way that the General Theory of Relativity has been proved to describe the facts of gravity.
(Also, why mention Darwin at all? Darwin's words could disappear from history tomorrow and the modern formulation of the Theory of Evolution would be entirely unchanged.)
Lucy is not a hoax - otherwise subsequent discoveries of Australopithecus fossils would have not have confirmed here anatomical reconstruction. There are remains from better than 300 individuals from the various Australopithecus species that have been discovered in the past ~45 years.
Even if Lucy WAS a hoax - like Piltdown Man - it would be irrelevant. There are many other hominid ancestors of humans that have been discovered since then. Not to mention the discoveries of the other Homo sub-species (Neanderthals, Denisovans, Heidelbergensis, among others) that existed alongside us. As well as all the anatomically modern homo sapiens skeletons from as far back as 400,000 years ago.
I know why I, and many others, hold fast to the Biblically-founded concept of Creationism. Why do you hold so fast to Evolution Theory?
Because it's a thoroughly tested explanation of the diversity of life, and not believing it requires me to instead believe ridiculous conspiracy theories and/or creation mythologies that don't line up with observed reality.
Even when I was a religious person (Catholic), I saw no reason to believe the Christian creation account was anything other than allegorical. And neither did any of the teachers at the various Catholic schools I attended, including the priests.