I cannot help thinking that blockchain is a solution still unsure of the problems it is meant to solve. Banking seems ripe for digital harvesting but insurance?

The margin benefits have to be higher than the marginal costs and the latter have a habit of increasing. Proof of work exponentially increases the need for computing power, bandwidth and energy consumption. 

Not every problem needs a blockchain as a solution. Blockchains cost money in terms of processing, storage and replication technology. In the case of a decentralized cryptocurrency, such as bitcoin, the blockchain-like concept is an essential characteristic to build a viable design, but for other problems we need to ask if the blockchain features are doing something valuable.

For many situations a single digital record shared securely and efficiently across all the stakeholders in a supply chain may provide a better option than a decentralised ledger over large peer-to-peer networks.

Take insurance again:- Will customers really want to make micro smart contracts across events and activities each day or deal with a world-class carrier which delivers flexible and cost-effective cover across all requirements?

Cost, User Experience and Trust are all key and Blockchain will not be a solution for all especially as it scales up. There are some very good lessons below from the world of IoT which has been around for over 20 years