In California[0] we audit 1% of all ballots, regardless of the outcome.

[0] - https://www.sos.ca.gov/elections/voting-systems/oversight/co...

What does that prove?

Your electronic voting machine could completely tell you the truth about every ballot you ask it about, but lie about the total.

Because we count an entire precinct and check the totals. We don't just ask it what it got for individual ballots.