But you still need to validate the paper side, so that benefit is removed unless you trust it alone.

And requiring a large amount of manpower is a benefit of paper voting, not a problem. In the grand scheme of things it's a miniscule amount of work, and it ensures freedoms and laws for generations to come. This isn't an area where efficiency matters. The more manpower it takes, the harder it will be to "hack" it without being noticed.

You only verify a small subset of the paper ballots. You randomly sample to verify the electronic records.