If so, then no. It is not time for that.
The best I got is if you are trying to do an old-school style video game asset/save game storage. But even then, the value in just using sqlite or even parquet is really high.
There's so many really good data formats that deciding on a new one at this point seems pretty silly. Particularly because what you sign up for when you make a new one is losing any and all tools that could be used to work with and diagnose that data.
That's interesting. Maybe to decrease latency the LLM could "cache" it's build of it's database and reuse in between instances. It could host this artifact on a "hub" of git trees and then any new use cases that come up, can be added to this git tree. Then it can possibly be reused in different use cases.