The way I look at it Bitcoin will be the dominant Store of Value for a very long time and there is no need to change the POW. You can read https://hackernoon.com/asic-resistance-is-nothing-but-a-blockchain-buzzword-b91d3d770366 for a great reasoning.

POS based blockchains will derive their value out of the problems that they solve and not as SOV.

DPOS based chains will empower the web applications right away without waiting for POW based and POS based blockchains to address their performance issues. Current examples are Steem and EOS.

So I think each of them have their place. We just need to make sure that the spams in each of this category are called out thats all ;)