The nature of the ledger of the blockchain can be seen by others but at the same time it is safe because it cannot be changed by just anyone. This is what makes the Blockchain dualism.
This fact is also an advantage because it can make business integration between companies more efficient. Everyone can trust each other because all data can be recorded properly, can be seen by others even though there needs to be special access first.
If the data can be replaced, there will always be a track record because the concept of the chain itself cannot be replaced, it can only continue to be added.