The storage based blockchains don't use storage space as a means of verification- they're storage product focused (you buy/rent/use/sell storage space on the platform as a commodity). That's not what Chia does; it seems like its primary use will be store of value/transactions like Bitcoin. It's the "green" alternative to BTC- I wouldn't call Filecoin, Storj, Sia, Maidsafe, etc. competitors to Bitcoin (and I don't think they're trying to be that).
While Lisk, Nav, Dash, etc do use alternatives to proof of work, what Chia is doing, from my understanding of what they're saying, is using the lowest cost alternative to proof of work, which is proof of storage (disclaimer, I don't know the math behind proof of storage, just that it's their alternative to PoW). However, proof of storage alone has some inherent vulnerabilities so they compensate with another mechanism, proof of time (again, not sure of the math).
Edit: punctuation
While Lisk, Nav, Dash, etc do use alternatives to proof of work, what Chia is doing, from my understanding of what they're saying, is using the lowest cost alternative to proof of work, which is proof of storage (disclaimer, I don't know the math behind proof of storage, just that it's their alternative to PoW). However, proof of storage alone has some inherent vulnerabilities so they compensate with another mechanism, proof of time (again, not sure of the math).
Edit: punctuation