Post #3354855

Only the last few blocks are “rewritable,” which is why a certain number of confirmations are a necessity. Going any further back than that, would be a completely different chain - a fork. The last of of those occurring on Bitcoin was thirteen years ago when it was still encountering growing pains due to an uptake in usage. Forks of more than a couple transactions are not a frequent, regular occurrence by any exaggeration, so for all intents and purposes of modern crypto usage, it is immutable, not rewritable.