Yeah something can be potentially net good for a company but still be a COI. If I'm in charge of awarding military contracts and I give it to a armaments company my son is a VP of, and I didn't disclose to anybody that my son was a VP there, this is a clear COI even if I later argue (and people agree with me!) that my son's armaments company is best suited for the business.

At the very minimum I should not be the one to make that call.