First, I don't consider that immutable. Second, that isn't true for all databases, often you have to set it up and turn it on, and think about what you're doing

First, I don't consider that immutable. Second, that isn't true for all databases, often you have to set it up and turn it on, and think about what you're doing as there are considerations for storage and backups. Third, it isn't like you can just get the data back magically and without effort. It can be a problem to hunt through. It can be an enormous amount of data.