I've seen some coins here talk about using Moore's Law in difficulty calculation. The thing is, Moore's Law will no longer be applicable in a decade or two. The phenomenon of quantum tunneling prevents transistors from getting small enough to meet the predictions made using Moore's Law.
Are coins developed with this in mind? If not, their difficulties might rise beyond intended levels. Perhaps the magnitude of the rise would be negligible?
I think as computers evolve, cryptocurrencies will evolve. Difficulty algos can always be tweaked.