Well, it'll probably be a long time before the "bitcoin craze" is over since cryptocurrencies as a technology and an asset class are still in their infancy, but

Well, it'll probably be a long time before the "bitcoin craze" is over since cryptocurrencies as a technology and an asset class are still in their infancy, but it's hard to say how long proof-of-work mining will last. Personally, I'm most closely following what the Ethereum guys are doing with proof-of-work (see: https://ethresear.ch/ https://ethresear.ch/) but I'm also quite keen to see Chia's proof-of-space-time (an iteration of proof-of-capacity) or if something like proof-of-useful-work is possible. I think everyone's in agreement that PoW is expensive and wasteful, it's just a matter of developing//proving something that works better/cheaper...