They implemented a block store with replication from scratch? That's kinda brave, considering that that's a project big enough to justify full startups for!
However, the folks at Oxide are at the top of the game for this space with dozens of years of experience in building and testing such systems. Secondly Oxide's crucible stack is completely written from scratch in Rust, which dramatically reduces failure modes common to such stacks, which are often written in C / C++.