They are conflated, but the correlation isn't just that one can be used to pay for the other. IPFS is increasingly becoming the "content layer" for blockchains,

They are conflated, but the correlation isn't just that one can be used to pay for the other. IPFS is increasingly becoming the "content layer" for blockchains, since it's not efficient to store content (like images) in (most) blockchains. Having a kind of literally global GUID that can point to arbitrary decentralized content is fantastic. While the credit for it absolutely goes to IPFS rather than to cryptocurrencies, it does happen to be perfectly suited for any kind of application you may try to build on a cryptocurrency blockchain.