I use ChatGPT (with GPT-4) all the time for coding. I've developed a feel for the maximum complexity it can handle and I break down bigger problems into smaller subtasks and ask it to write code for them (usually one function at a time, after a detailed explanation of the context in the beginning). I need to review and test everything it produces thoroughly but it's worth it. Sometimes it helps me complete tasks that would have otherwise taken a day to complete in 1-2 hours.
I also have Copilot installed but it isn't as useful as ChatGPT. It's nice to get a smart completion sometimes. I'm even in the Copilot Chat beta which uses GPT-4 and I find it inferior to ChatGPT with GPT-4.
I never touch GPT-3.5 anymore. It hallucinates too much and the quality of the output is very unpredictable. I guess most people who say AI is useless for coding haven't tried GPT-4 yet.
Oh, and something else. In my experience, the quality of the output depends a LOT on the prompt. If you give a clear, detailed description of the problem, and try to express your intent instead of the specifics of the implementation, it usually performs very well. I've seen some people at work write the worst, sloppiest prompts and then complain how useless ChatGPT was.