So ethereum goes for RANDAO. The disadvantage with randao is that the last validator in the commit-reveal scheme is able to hold his contributed value back and thereby influence the random outcome. Ethereum is trying to overcome this by using verifiable delay functions.
Why all that hassle? Why not just go for threshold signatures like Dfinity? What's the drawback?
Some link to a statement from Vitalik Buterin on this would be higly appreciated. Otherwise if you can explain it it's also fine