alt Hacker NewsSpeculating: local ssds aren't as valuable in the cloud since they're effectively ephemeral. If the instance restarts, it would lose its storage. Trying to keep a workload affinitized to an SSD or to migrate data to a different SSD when an instance moves increases cost prohibitively.
For a lot of use cases such as caching (e.g., the ephemeral caching layer in Snowflake), ephemeral storage is good enough. If you really want to, you could also achieve persistence by replicating to multiple instances (afaik this is what DynamoDB does)