This is a very interesting development that I'd like to learn more about. Whenever I've played around with writing databases (just as toy projects) I've always done so using RocksDB or something similar as a backend. This "thick client" model, though, seems to have a lot of potential benefits, most notably no need to worry about disk space or volumes (so say goodbye to a bunch of config parameters) and no need for a tiered storage setup or S3 migration tools (already accomplished!). Not ideal for most use cases but intriguing for some!
There are a lot of issues though with S3, latency, poor performance for small reads / writes, timeouts, api rate limits, api costs, and consistency issues poorly understood by third party developers.
A "thick-client" also doesn't perform well unless that client is located on a node in the same region. I think as with everything it works well in some cases and not well in others.
