Optical scanners have a very good cost-benefit in terms of accuracy, complexity, transparency and usability.
If you refer to paperless electronic voting, it will be always vulnerable to malicious insiders. In order to possibly prevent that, you would have to lock it down in such a way that no one would be able to audit the result after the fact, undermining the sole purpose of a public election.
https://www.usenix.org/conference/evtwote13/workshop-program...
Optical scanners have a very good cost-benefit in terms of accuracy, complexity, transparency and usability.
If you refer to paperless electronic voting, it will be always vulnerable to malicious insiders. In order to possibly prevent that, you would have to lock it down in such a way that no one would be able to audit the result after the fact, undermining the sole purpose of a public election.