Why would an optimized (optimized for run time speed? optimized for low memory footprint while running? optimized to minimize the likeliness of hash collisions) version of the same BLAKE entrant be more useful?
BLAKE2 is an improved version of the SHA-3 finalist BLAKE. Like BLAKE or SHA-3, BLAKE2 offers the highest security, yet is fast as MD5 on 64-bit platforms and requires at least 33% less RAM than SHA-2 or SHA-3 on low-end systems. I can find applications in cloud storage, software distribution, host-based intrusion detection, digital forensics, revision control and embedded systems https://blake2.net/blake2_20121223.pdf