Ah I see, my bad. You mentioned Ruby on rails and GraphQL so I assumed you were talking about some kind of MPA situation.
Yeah htmx doesn’t replace data APIs for sure. Still not a fan of GraphQL for that purpose for the reasons above. There’s a lot of good options for RPC stuff, or even better, you can use message queues. GraphQL is just a bad idea for production systems, IMO.
I wasn’t suggesting making JSON “REST” APIs (not actually REST, more accurately you might call them JSON data APIs or something). I meant protocols that are specifically meant for RPC, like gRPC, JSON-RPC, etc. Or message queues like RabbitMQ.