My main concern about Copilot use is that, unless you're in a race to quickly produce a minimum viable product, it doesn't optimize the hard part. The initial coding is a very small piece of the work.

Code has to be designed, maintained, and extended, and for supportable code we want to have someone on the team that understands it well. If we want the code to be flexible, we want design decisions to appear in as few places as possible, ideally one. Copilot as an auto-complete, where it just helps fill in function names and the like, is fine and helpful (but IDEs do most of that already). But if it's used to write larger code chunks we quickly have the problem that there are code sequences no one on the team understands (it passed the tests though, yay!?) and we wind up with bloat from a lot of copy-paste like code.