[lmm]

> the relational model is very powerful, albeit quite abstract, and most data we need to deal with can be made to fit into this model

Maybe, but it's awkward. Graph or tree structures are still painful to store in relational databases, and a lot of problems turn out to involve those shapes.

> We have a working, declarative query language that Just Works(TM), for which we have written very good optimizers.

Maybe, but the tooling is still terrible. Where are the libraries? Where are the IDEs? Where's the integration that makes it easy to call procedures in my application language from SQL and vice versa? General-purpose programming languages have got better and better in the last 25 years, while SQL has stayed static.

> So, to sum it up: Exactly why should we abandon this?

Look at the ORM problem. Why do people continue to use these horrific bloated, leaky tools? Because it's really nice to be able to store and query in the native language of your application. We need storage tech that's better at supporting this.