The certainty comes from our history, financial state, fanbase, etc. Agnelli definitely was an important factor, we had built our own stadium, we were in a healthy financial state, and the desire to get back on track was definitely there (unlike what is the case in say Milan). Conte could have been another Del Neri, we trusted an inexperienced coach, but even if that had happened, we would have fixed it for sure. We would have tried other ways, possibly hiring a more experienced/better coach. I admire Conte for what he did for us, I am aware of his talent as a coach and a motivator, and I'm happy that not only was he the one who helped us come back, but we also helped him with his career. But I refuse to think that he was a savior without whom we would have been a mediocre team in serie A.
The way he conducted himself when he left us and after that made me dislike him but i'm definitely not butthurt (as all seem to suggest here) because we anyway ended up with an excellent coach and we did very well without Conte. My reaction to his celebration is independent of how I feel about him. I have my reasons to be grateful for the time he was at Juve, I have my reasons to be upset with him, I have my reasons to cheer for him in EPL, and in this particular case I have my reasons to find his celebration very fake and yuck worthy