No one cares that blockchains are immutable, that doesn't mean that information written there is correct. Just that it was written on X date and the content. You could find proof of the biggest scandal of all time and post it on the blockchain so "the man" can't stop the word from getting out but 99.99999999% of readers would read a version presented by a simple web server and with the value cached in a closed database or memory. Which if the government wants to take down, it can. And if that does go down, no one will save a link to the entry on the blockchain. And on the flip side I could write obvious falsehoods in the same way. Blockchain provides no value for legal attestation nor information distribution.

In practice, the vast majority of blockchain ledgers record the history of scams, penny stock style trading and money laundering attempts.