Indeed, but it's not a new idea. This is Bigtable's architecture after all, which is now 15 (?) years old. There are a bunch of advantages: DB developers can fo

Indeed, but it's not a new idea. This is Bigtable's architecture after all, which is now 15 (?) years old. There are a bunch of advantages: DB developers can focus on the DB, not the storage layer (which is in many ways much harder to get right), you can scale storage and processing independently, you can easily support different tiers of storage (SSD/HDD). But by far the biggest advantage is operational. Your DB is now stateless! Nodes can die and be replaced in seconds, because they don't store any data; this makes designs like Bigtable's much more practical. You can quickly scale up the processing to deal with spikes without spending hours re-replicating. Operating the storage layer is still inherently challenging, but just has to be figured out once for all your DBs and other processing systems. While performance can take a hit, this can be mitigated by local caching and good internal networking. It isn't able to meet the lowest levels of latency (sub ms), but in practice it works great for web applications.