Graph databases don't provide an advantage over well-architected relational DBs

I've never heard a convincing argument for graph databases.

What specific tasks does a graph database perform better than a typical postgres database?

I don't care about queries that are easier to read - I'm looking for performance, particularly under load.

A lot of qualifiers there. The relational database needs to be "well-crafted" and even then is better in "most cases".

Technologies can have niches.