Slowness isn't always a desireable property of cryptographic hashing. Generally you only want that property when you are trying to do some kind of key derivatio

Slowness isn't always a desireable property of cryptographic hashing. Generally you only want that property when you are trying to do some kind of key derivation from a human-generated password. In plenty of circumstances you want them to be fast, but hashes that have the desired security properties are all slower than the hashes designed to be fast and work well enough with non-adversarial input.