The Buddha actually taught Emptiness/ Śūnyatā
Yes—but there’s an important historical distinction.
The historical Buddha (early Buddhism): The earliest Buddhist texts strongly emphasize anattā (not-self) and dependent origination. The Buddha teaches that the components of a person are not a permanent, independent self. He also uses “empty” (suñña) language, particularly in the Pāli Nikāyas, but not yet in the fully developed philosophical sense of śūnyatā found in later Mahāyāna Buddhism.
Mahāyāna Buddhism: Centuries after the Buddha, śūnyatā (“emptiness”) became a central doctrine. Texts such as the Prajñāpāramitā literature and thinkers such as Nāgārjuna developed the idea that phenomena lack inherent, independent existence.
So: Saying “the Buddha taught śūnyatā” can be correct within some Buddhist traditions, but saying “the historical Buddha taught the later Mahāyāna doctrine of śūnyatā in exactly its developed form” would be historically anachronistic.
There is actually a fascinating connection: early Buddhist “emptiness” and Mahāyāna śūnyatā aren't simply unrelated doctrines, but scholars debate exactly how the later concept developed from earlier teachings.