[acdha]

It might be a bit strong — I would phrase it as “What does a blockchain do better than the alternatives?” — but I think it's justified in this cause because of how inefficient blockchains are for most problems. It's not just the cost of all of the extra hardware but also the design impacts of what operations you consider fast and the reliability impact of a shared global view.

In particular, in this case the question I'd be asking is “how is this better than PKI?” because that can do the job with multiple orders of magnitude less overhead and would be suitable for use in scenarios with limited bandwidth or which are completely offline, which is realistic for voting.