Ideally an electoral system should have the "none of the above" option. If it gets the majority the elections are repeated with new candidates, and previous ones are disqualified for a number of years.
When you vote in private, on paper, none is always an option. You can deposit a blank form, a form with 1 in every box, a form with zero in every box, a sketch
A national RCV race would be an absolute nightmare to count if it ever became remotely competitive. Approval Voting is better in general, but especially for big, competitive elections.