Can blockchain data be deleted?

Blockchain comes with the concept of keeping the data or transactions decentralized. This means all your data is recorded forever in a network of computers. Data, once sent to a blockchain network, cannot be deleted or removed from all the systems.

I mean, if you somehow managed to delete every existing copy of the entire blockchain that exists in the entire world, then it would all be gone, obviously. But you cannot delete a single block from the blockchain.