The words of every junior dev right before I have to spend a weekend undoing their crap.
I've been there too many times.
There are always edge cases you need to account for, and you can't account for them until you run tests and then verify the results.
And you'd be parsing billions upon billions of records. Not a trivial thing to do when running multiple tests to verify. And ultimately for what is a trivial payoff.
You don't screw around with infinitely invaluable prod data of your business without exhausting every single possibility of data modification.
It's a piece of cake.
It hurts how often I've heard this and how often it's followed by a massive screw up.