zcash frequently complies with regulators and doesn't have good privacy by default (privacy is opt-in). Coupled with lower usage compared to monero, it results in a really low anonymity set.
It's very centralized and they keep making deals with regulators, that's why zcash is getting back on exchanges it was previously delisted.
Technically, zcash has better privacy since zaphir shields are superior to blinded signatures (used by monero). Monero can potentially upgrade to zcash's zaphir but that requires a hardfork.