>persistence to disk, WAL, crash recovery, indexing, vacuuming (you're using tombstones for your deletes, right?),

The point of Raft is that you write your service like it was a single instance, using SQLLite or non relational equivalent, and then use Raft to run a distributed system that can have redundancy, all without additional infra involved, and for the vast majority of the use cases (i.e some backend or some web app service at a startup), this is more than enough, considering there is enough low level stuff in drivers and kernels to make data reliability pretty high already.