>I corrupt an old frame that is not needed by the database at all

1. How does the database know that.

2. In your example Alice gets the money from nowhere. What if another user had sent the money to Alice and that frame get corrupted. Then you just created 10,000,000 from nowhere.

At the very least, rolling back to a good point gives you an exact moment of time where transactions can be applied from. Your example is very contrived and in a database where several transactions can be happening, doing a partial recovery will destroy the consistency of the database.