The big boost, that I think parent is alluding to, is for rusty (not Rust!) languages in the toolbox, where you may not have the standard library and syntax loaded into your working memory.

As a nudge, it's a great idea. As a substitute for vigilance, it's a terrible idea.

I suspect that's why they named it Copilot instead of Autopilot, but it's unfortunately more likely to be used as the latter, humans being humans.