I won't say copilot is completely useless for code. I will say that it's near useless for me. The kind of code that it's good at writing is the kind of code that I can write in my sleep. When I write a for-loop to iterate over an array and print it out (for example), it takes near zero brain power. I'm on autopilot, like driving to work. On the other hand, when I was trialing copilot I'd have to check each suggestion it made to verify that it wasn't giving me garbage. Verifying copilot's suggestions takes a lot more brain power than just writing it myself. And the difference in time is minimal. It doesn't take me much longer to write it myself than it does to validate copilot's work.

"Copilot is really good at things which I already know" and that is perfectly fine