Comment by Deadron

Auto generated client code is nice in theory. In practice I find it only really useful as a starting point. There are enough choices to be made in writing even a simple HTTP api that its unlikely that a generic tool will generate useful code for a given application. This could include library usage (http client, serialization, logging, DI integration), async vs sync, logging requirements, tooling support for generated code. If you are in a language which has established std libraries and patterns this is less of a problem, but in something like Java that has evolved in all these areas over the years it can be a real problem.