One of the issues with graphql is that it doesn't use HTTP semantics. Errors are 200 status with an error field in the body. Queries are POST /graphql for everything (ok, so they don't have to be, but once you've got anything in your system that needs to go over a POST request, everything else will).

This is problematic in any environment which expects those arguments to have been settled a decade ago and has built its monitoring around them. Ask me how I know.