You mean when you became friends with the Winchesters and went against Heaven for them?

[ Jack did know the basic foundation of how they all connected, and that Castiel used to be a loyal angel and eventually changed priorities over time. He was at war with Heaven in a lot of ways in Jack's time, even killing some of the last remaining angels to protect Jack. But Heaven was a shadow of its former self, almost all the angels are gone now. Jack doesn't know what happened to the ones he made. ]

I don't think it would have been better. I know things are difficult but the person you are now is better than being one of the average angels. You think for yourself, you love people.