"Unlike Cassandra, Kudu implements the Raft consensus algorithm to ensure full consistency between replicas"
Cassandra does offer transactional consistency in the form of PAXOS that achieves the same goal. Additionally PAXOS or RAFT based consistency models aren't really necessary if you're willing to accept out of order processing and adopt idempotent data models; you only need quorum based consistency.
I'm curious to see what your throughput was in TX/s not just bytes/s in order to get a more apples to apples comparison.
I think you meant able to adopt those things. Those techniques are tenable and even excellent in some domains, but completely impermissible in others.