if zksnarks work as outlined, they offer far greater privacy with state of the art cryptography, see https://blog.cryptographyengineering.com/2014/11/27/zero-knowledge-proofs-illustrated-primer/.
zcash stable hasn't even reached its first birthday, is the first real world application with mass public exposure using zero knowledge proofs and is being used more as speculation instead of day-to-day purchases.
we still need to give it time to mature and be torn apart by others to prove its worth before giving it the go ahead.
in the meantime, i can buy things with monero, walk the blockchain and have no clue as to what tx went where and how much, seeing as all is private by default.
with zcash where you have to opt-in to use a shielded address, its had this knock on effect where there are more users sending tx's in the clear, which impacts the anonymity set of the rest of the network who choose to shield; what part of "anonymity in numbers" did zcash not understand?
this is precisely where monero shines, all tx's are sacrosanct, fungibility is king.
ring sigs partly remind me of the -R flag from openpgp, probably due to the brute like manner in which it iterates the public keys.