Oh man, Trespass is one of the best
albums of all time. No way Collins
could have done that.
He's pop. That's it, really.
You are forgetting his production efforts.
BTW, I consider
Trespass to be one of the most overlooked albums of the era. If you are going back to the beginning of Genesis, though, you won't find Phil's influence. When he came along, Genesis was practically dead and he brought it back, sort of, from a stretcher.
Trespass helped a lot, but he was out of that loop, as far as I know.
See, if you knew a bit more about how record labels controlled the business in the seventies and eighties it would be clear to you how and why he made the effort. Just the fact that he was able to bring them back to life is amazing to me, commercial interests or not.