I've found that this is a simple and effective way to handle relational data either in REST or Graphql. But imagine having to traverse trees, filter on data of different types and levels. Sort and filter on edges. I mean it can get pretty complex and I am not saying that REST would be easier on those complex cases.

In my opinion graphql and rest can both be super cute in simple everyday queries. But I am thinking that people are creating databases like postgres, mongodb, neo4j, etc, are doing exactly that. Trying to give us the power to query our data efficiently. Why not be able to expose directly the database and just add a layer for security, control, decorating and other stuff that would add value. Why rewrite databases?