Earlier quoted context omitted.
But tampering with a paper-only election requires physical interference and working across many different locations. It is much easier, if you have the talent, to break into an electronic election.
That's why you use both. Paper for tallying and electronic for auditing. I used to think electronics wouldn't help but now I'm starting to be convinced.
The simpler solution is to hire more counters. I can't imagine that'd be more expensive than developing custom hardware & software.