You would have to hack, undetected, into thousands upon thousands of computers on which copies of the block chain ledger are stored. It’s not possible. NFTs can be lost and they can be stolen but they can’t be pirated.
The blockchain assumes it's too big to fail. Unfortunately, there are a lot of sufficiently large bad actors who could prove this wrong.
The people who say the blockchain "can't" be hacked are either promoting cryptocurrencies, or lack sufficient imagination.