The solution is to devise a Proof-of-Work mining mechanism that isn't so resource hungry. But then, isn't that what every other new ICO aims to do?!
If we ever chance upon a Proof-of-Work that is as satisfyingly rigorous and meticulous as is the case with Bitcoin, then and only then will Bitcoin depreciate to the status of 'toy money'. But, if Bitcoin can happily co-exist with smart contract equipped Ethereum, it may well outlive others is well!
I agree that we need a less power hungry PoW solution but also note that is sort of PoS which on many networks requires little computing power. I don't believe Bitcoin and Ethereum mining will be possible or sustainable for much longer because of the cost vs reward and I don't think the world's power grid can take much more (this is why Ethereum is going Casper/PoS).