In my mind the primary issue is the users at this point, not the tech.
If we could reasonably expect grandma to properly secure her private key, and register its public key with the government, we could likely do reasonably secure blockchain voting, with government still performing validation of personhood.
This problem isn’t going to go away with time either, it’s not really an issue with “boomers” so much as it is older people are just easy to manipulate.
There are still other logistical issues, such as dead people voting, governments confirming “personhood” of fake voters, etc, but I do think that transparency in the vote could help a lot.
It’s a complex issue, but I believe the primary problem at this point is the tech-savvyness of users, not the tech itself.
All of that being said, I also think people highly underestimate the issues with our existing voting systems. It’s easy to find potential problems in a new system, but we often forget that the new system just needs to be better, not perfect.
One thing I’d love to see is direct democracy, but users can choose to join “voting pools”, where they essentially delegate their voting weight to a hopefully more informed group they agree with.