-Decentralized Identity (see W3C DID)

-Votes aren't verifiable by everyone.

-Privacy

Just to name a few.

I briefly studied voting systems at university and the studies behind them

The Duverger's law for example states that there is a strong psychological component, beside the mechanical one

If the vote process is effortless the elector is less involved and that's why going to the ballots is still the favourite way to engage voters

If a system promise to be unbreakable and solve every voting fraud problem, voters will be less careful when voting

Etc. Etc.

Elections are not primarily a technical problem, it's a social rite they are like the rites of passage in ancient tribes

Governance is really work in progress but I'm happy to see that people are taken this on. Many crypto projects are building in governance into their tokens and networks. I think we will see voting on the blockchain within in the next 5 years -- probably done by smaller countries or municipalities first. We will get more data and information about tech. vs social rite. Moreover, being on the blockchain doesn't mean that people can't exp. the social rite by going to vote.