Holomorphic encryption is not about breaking existing encryption. It’s about building new cryptosystems that allow specific operations that current cryptosystems don’t. The goal is to build a cryptosystem where given a function f such that f(x) = y you want to have an encryption scheme where someone who doesn’t know x but knows encrypt(x) can calculate encrypt(y) without learning anything about x or y.

If someone found a way to do something like that with a current cryptosystem it would be considered broken.