Actually it is good that nobody can get proof for their own vote. Thus votes selling is harder - provider cannot provide anything to seller. And yes, taking pictures of your own ballot is not allowed over there. Camera shutter sound may cause quite an issue.

Another issue is employers pressing workers to vote for certain politician etc. They could flat-out ask for one's blockchain ID. With paper voting, there's no way to valid way to get proof.

Paper voting trust is based on crowd trust. Anyone can check voting make sure everything is going smoothly. Don't trust your local voting committee? Go and sign up to volunteer!