[leppr]

Check the "Simulation" part of the Snow White paper I linked above for instance[1]. You're right to ask that, because indeed most Proof of Stake algorithms either have weaker[2] or slower[1] safety guarantees.

[1]: https://eprint.iacr.org/2016/919.pdf#section.5

[2]: https://docs.zilliqa.com/whitepaper.pdf