Bitcoin the most secure public ledger in the world proves that every participant in the blockchain can verify and see billion+ valid transactions. Trust in fully decentralized and transparent elections is not a technical issue!
I still think _ergonomics_ of making sure every eligible voter can use the system is far more important that making it {immutable, distributed, transparent}.
Also, the immutability property is a double edged sword as someone losing control of their wallet secret key would lead to a leak of everyone they voted for. Or worse yet, if voter ID is tied to wallet ID instead of government-issued ID, one organization could go around stealing private keys in order to steal those ballets.
The BTC ledger is pretty good, but it is fallible —- mostly because a human has to control the keys and the UI apps that make using the wallet for transactions are far less secure than the core BTC protocol. Good luck teaching a 90 year old person who hates computers how to vote using their BTC wallet.
Also, the security of BTC isn’t infallible. Once someone finds a weakness in the system, they will quietly abuse it as a 0-day for a while before anyone notices it. Elections should be robust against any single point of failure, and they are. The BTC wallet is until it isn’t.