Github Copilot is very useful as a "mind-reading" autocompletion if you are writing correct code and you know what you are doing.

Or if you have the general idea on how the code should be, but you don't know how to use the api for a specific library, you can write a comment explaining what you want the next line to do and copilot will write the code to do that.

It works best if you have well structured commented code and source code available for the main dependencies, also it doesn't work the same with all languages and programming styles.

Regarding debugging, it catches oversights that you would catch too if you were to read carefully the code, it is not very good with complex issues.

Overall i think as a developer you should aim to integrate with ai tools and not to use them as a replacement for yourself.