@corbin ChatGPT4 writes better unit tests than 3.5. Using the bots is a matter of finding their sweet spots of what they can do. That they're catastrophically bad in one area doesn't mean they're bad in all areas.
GPT Builder/Custom GPTs are little more than a mashup of an initial prompt and plugins (tools). I think for most cases plain chatgpt is better. Maybe in a year they'll get the assistants right.