Paper ballots solve the most important problem: they can be counted by hand in case of disputes, without having a single computer at hand. That is the essence o

Paper ballots solve the most important problem: they can be counted by hand in case of disputes, without having a single computer at hand. That is the essence of the problem, that is what separates systems with voter-certified paper trails - whether those are machine-produced or the result of the voter using a writing implement or paper punch to mark a sheet of paper in some way - from systems which lack such a trail. Computers can be used to produce a quick tally but the final, legally valid count should be done by hand with observers from all parties involved in the elections, preferably by parallel counting teams from 'opposing' parties so the results can be compared. Voting is in itself a simple process, even in the USA where the ballot can be filled with multiple options. Computers are not simple, are not transparent and are not understood by the majority of the population. They can be used for quick counts, for producing fancy graphics, for doing all sorts of statistical trickery and whatnot but they should not be relied upon to produce the final results of an election.