I hate to say it, but it's completely changed how I code. It's a massive help. I get it for free because I have enough open-source stars on github or something, but I'd pay for it if I lost that.
I can understand why you'd want to avoid it based on principle reasons though.
Everyone at my work uses it. If someone stopped using it, everyone else would think "why are you making coding harder for yourself."
I know @Eli Mellen said they're not looking for judgement of the tool, but to add to what others have said:
I'm very forgetful when it comes to remembering APIs, even my own ones. So it's like autocomplete on steroids. It used to compete with autocomplete, but I've heavily tweaked the settings so that it doesn't. You can fully customise how and when it appears.
I do so much copilot prompting within my editor. "This function downloads an object as a json file". Previously I would look it up on stack overflow.
It's best at writing tests. It made test-writing a lot more fun for me too!
In my personal projects, I've started to keep my code in fewer, bigger files because Copilot seems to behave better when you do that. In my personal projects, it works really well.
It does worse for my job's projects. It tries to use APIs from older versions of tldraw. It must have loads of tldraw version 1 projects in its training data, and it uses that instead of the new version 2 APIs in the repo I'm working in. I've got very good at learning the v1 to v2 equivalents