I’m not sure there is any way to know the average COI for an entire breed. Obviously different breeders have very different standards, and there could be an individual dog with a high COI but used in a breeding program for a very specific purpose.
I am not a breeder, but my oldest dog has been used for stud service, so I’m kind of in the breeding world. My understanding is that COI in itself isn’t all that useful or important - because all wild dog packs probably have pretty high COIs - clearly it’s not a death sentence.
What is a bad thing is high COI without health testing and other selection criteria to eliminate the ones that might pass on hereditary conditions that are undesirable. In a natural selection situation, those poor specimens are either not bred because they lack some quality, or actually get sick or injured and die and are eliminated from the breeding pool. With resources available now, as well as ways to track pedigrees, breeders can use other tools rather than just COI.
That said, the breeders I know are careful to keep the COI fairly low, but that doesn’t mean that a deliberate match might not have a higher COI from time to time - sometimes those are intentional to “double up” on particularly good traits, and then go back out again.