Article author here. Great questions, should have explored the randomness beacon more. Ethereum uses [RANDAO](https://github.com/randao/randao https://github.c

Article author here. Great questions, should have explored the randomness beacon more. Ethereum uses [RANDAO](https://github.com/randao/randao https://github.com/randao/randao), which is a distributed commit-reveal scheme where participants in the generation post a hash of their data on the commit portion and then at a later timestamp reveal the data preimage, and get slashed if they do not reveal a correct preimage. Then all participant data is aggregated together. This means if there is at least one honest participant the generation will be random. A supermajority (2/3rds) of validators is required to finalize a block, in case of a 50-50 network partition blocks would stop being finalized and attestation rewards would stop. Non-participating validators would slowly leak stake through the inactivity leak until online validators once again had a supermajority. This is the "self-healing" mechanism that allows both safety and liveness.