[ptttr]

The original question made this mistake probably because the poster didn't know it but Pathom is the actual alternative to GraphQL-based APIs. Datalog solves a subtly different problem of querying the data, while Pathom/GraphQL/REST is about exposing the data (interfacing?) as API.

It's more like:

Pathom vs GraphQL-based API (vs REST)

and

Datalog vs SQL (vs NoSQL)

The mainstream is in the process of migrating from REST to GraphQL, but I think Pathom could be the black horse in this race. Just watch the last part of Wilker Silva's The Maximal Graph talk to see the potential: https://youtu.be/IS3i3DTUnAI?t=2080