All problems with all software are developer issues. Technically, we could do everything in Assembly, but we don't.

Ideally, a technology needs to solve as many problems as possible while introducing as few problems as possible. That is why I am not sure every organization should use GraphQL.

If someone came to me from an SMB and asked "should we switch to GraphQL" I would first ask what problems they have, and what they believe GraphQL will solve. Then make an informed decision, the answer is not "yes, you should always use GraphQL".

That wasn't the question as posed though. It was 'regarding its technical basis, what issue does GraphQL have?' and rarely do I ever get an actual technical problem with how graphql is structured.

REST has at least 1 inherent flaw in its model, which is 1-1 API resource coupling.

Now, if we want to talk about perhaps skill threshold? Yeah, GraphQL requires a higher level of confidence and experience to use correctly.