Proof of Stake in a Block Chain

There are two different versions of consensis in the realm of proof of stick, right? So when i see proof of work, par about nockomotive, everyone, everyone playe a giant sutpio to win a chance at asetating the next block. The moment a block is submitted it is final, as you cannot roll back. You can't yo, can't roll a black bact. There's no probability associated with how deep in the blocktine is it because of the nature of how these agarithms were and so on. Can we confess for the clock? 20 years from now, we're old and grey, and for still some reason