While 0x has established itself as part of the core infrastructure for building out Ethereum’s decentralized finance ecosystem, the utility of its native token ZRX remains muted. The 0x white paper outlined two core use cases of the ZRX token (1) governance and (2) transaction fees. So far, there is no formal governance feature in the 0x protocol — any implementation of it is in the very early stages. The cumulative transaction fees charged and denominated in ZRX by relayers since the project's inception doesn't signal much utility either.
According to 0x tracker (a 0x community supported explorer), cumulative fees charged in ZRX and collected by relayers since August 2017 has totaled less than $3,300 total, with the top three days of fees making up ~25% of the total. Meanwhile, no material $ value of ZRX has been collected since October of 2018.
Source: 0x Tracker, The Block
Just last month, Tian Li, CEO of decentralized exchange DDEX, announced that his team is forking the 0x protocol — removing the ZRX token in the process. According to Li, the reason for ZRX token's removal is because "fee-based tokens create unnecessary friction." In theory, relayers could charge users transaction fees denominated in ZRX, but this was never a requirement built into the protocol. Since inception, the data has shown the lack of utility of this function.