CRC32 is slower because implementing it in software a way that exploits modern CPU's instruction level paralelism is non-trivial, also the obvious way how to implement CRC32 on 32bit byte oriented CPU isn't exactly cache friendly.
Are you referring to Intel's Slicing by 8 algorithm[0].
[0] https://static.aminer.org/pdf/PDF/000/432/446/a_systematic_a...
> I think the specific variant of BLAKE that directly competed with Keccack is slower
BLAKE is slower than BLAKE2 indeed. BLAKE also has more rounds than BLAKE2.