You're being facetious and you know it. It wasn't paper ballots that enabled the communists to hold on to power, it's that they didn't have any opposition, and their elections wouldn't be recognized as fair and valid by any modern standard.

Half-facetious. If a government really wants to hold on to power by force, they can do it one way or another - elections end up being theatre in that case anyways.

Except in Soviet Union terrorizing all the opposition parties/majority of voters was long, costly and brutal process. Online voting makes the whole thing cheap, easy, and undetectable.

And they got caught. Everyone knew the elections were rigged. With electronic vote you can get away with the crime and nobody's wiser.

Vote results are always really close to pre-election poll results. You can't really manipulate the results too much unless you somehow prohibit polling.