people have thought proof-of-work to death and what we have now is the best that they&#x27;ve come up with.<p>every other scheme that people suggest replacing it with runs into difficulties because you can&#x27;t predict the amount of time (roughly) it takes to do the work. in Bitcoin&#x27;s case, you CAN predict (roughly) the amount of time it will take to roll 3 1&#x27;s in a row when repeatedly rolling a 6-sided die.