You're making a lot of assumptions in this post. If you want to persist and query data structures, there are LOTS of non-relational databases that do that (e.g

You're making a lot of assumptions in this post. If you want to persist and query data structures, there are LOTS of non-relational databases that do that (e.g. Mongo). The "relational model being not a good fit for most apps" is a 40 year old argument, and was wrong then and wrong now, it's like saying "mathematics is not a good fit for X". In practice, fighting the query planner abstraction via query hints can be needed, but that's a pretty minor pain IMO. Inevitably for any long lived app, future requirements lead to unpredictable patterns of access or update occur and this is where the relational model has always shined.