GraphQL is extremely useful, if only to have strong type validation between disparate languages, via code generation. It can be a universal typed schema of your data against which you can use whatever server and client combo you want. It's like tRPC but you're not forced to use only TypeScript. I also have to plug this video [0], since many people think GraphQL somehow is a competitor to SQL and that it goes between…
The limited types in GraphQL kinda make that not very helpful. A RESTful API with JSON Schema or zod schema for it has much stronger types, and you can even make converting to better types be part of the zod schema.