I’ve had similar experiences at my last company with the generated C# code.
Ultimately built our own generator because we wanted to ensure specific behaviour for status codes in all of our clients.
We also published the generated clients as NuGet packages for our external consumers, the generated clients had the descriptions etc from the OpenAPI spec embedded in XMLDOC comments (C# code documentation) which helps developers a lot because it appears in IntelliSense in visual studio
Ultimately built our own generator because we wanted to ensure specific behaviour for status codes in all of our clients.
We also published the generated clients as NuGet packages for our external consumers, the generated clients had the descriptions etc from the OpenAPI spec embedded in XMLDOC comments (C# code documentation) which helps developers a lot because it appears in IntelliSense in visual studio