Thank you for the thoughtful comment! Comparing these specific features to using, say, a vanilla general purpose PL such as Python with an ORM and a SQL databas

Thank you for the thoughtful comment! Comparing these specific features to using, say, a vanilla general purpose PL such as Python with an ORM and a SQL database, it looks to me like the integration of primitives such as parsing, constraint programming and unification are far stronger. In particular, unification seems to be a material one that you mentioned -- to do this in SQL, you'd have to do contortions around an EAV model which could probably get you to the same area you would with prolog unification, but probably much less efficiently. It does seem like the answer to my question is "ergonomics and efficiency" which is a useful thing to know.