@thedesertlynx Elections rely on centralized government ID system. The government can create fake identities to manipulate the results, and it's nearly impossible to prove it (because no one else knows which voters are real).
Another reason is social in nature, and arguably even more important. The process should be easily verifiable, otherwise attacks can go unnoticed. With some training everyone can verify the process of in-person voting and manual vote counting. But blockchain-based systems with zero-knowledge proofs? I think there are maybe 100 people on the entire planet who can audit such system, and their objections can be easily ignored (it's already happening). Most likely independent audit won't be allowed for "national security" reasons.
What you get is a completely opaque system that shows a pre-programmed result.